Continuously Reinforced Concrete Pavement

A CRC slab will move extensively under the influence of changing environmental temperatures.

From: Advanced Concrete Technology , 2003

Processes

Geoffrey Griffiths , in Advanced Concrete Technology, 2003

22.2.5 Description of continuously reinforced concrete pavements CRCP

This form of construction has been developed from reinforced concrete pavements. Continuous reinforced concrete pavements are constructed as long slabs with longitudinal reinforcement fixed at the centre of the slab. Figure 22.4 illustrates a typical CRC pavement. The longitudinal reinforcement is intended to control shrinkage cracking. A nominal amount of transverse reinforcement is also provided; to hold the longitudinal reinforcement in place. Essentially a continuously reinforced concrete slab consists of a regular section of cracked square concrete plates connected together by the steel. The system is very similar to a mass and reinforced concrete; except that the cracks are formed in a random fashion and remain unsealed. A second feature of a continuous reinforced concrete system is that ground anchors are required at terminations. A CRC slab will move extensively under the influence of changing environmental temperatures. The ends of the slab are therefore anchored to prevent massive movement. If a continuously reinforced concrete slab is not provided with terminations a large bump or ripple will occur at the start of the bituminous material. Figure 22.5 illustrates a typical anchorage arrangement.

Figure 22.4. CRC pavement

Figure 22.5. CRC ground anchor, taken from the UK Highways Agency Standard Details.

Crack spacing is essential to the efficient operation of this type of pavement. Transverse cracks must be spaced between 0.9 in and 4 in centres; if the cracks are too closely spaced the blocks of concrete can fail in shear as punch-outs. Cracks can also be spaced too widely; if the cracks are spaced too far apart aggregate interlock is lost across the joint. Crack spacing is controlled by the longitudinal reinforcement content which is currently fixed at 0.6% of the section area.

The surface finish is a particular engineering problem associated with this type of construction. Several different types of finish are currently used. A patent form of construction known as Whisper concrete (Charon et al., 1989) uses an exposed aggregate surface to provide a running surface. Figure 22.6 illustrates a section of Whisper concrete. The top 40   mm layer of concrete is constructed in a thin overlay of high quality, air entrained 10   mm aggregate concrete. The surface is then sprayed with a retarding agent immediately after the concrete is laid. The surface can then be removed by wire brush as the concrete sets, thus removing the cement paste from the coarse aggregate matrix. Whisper concrete is very popular in mainland Europe but has been used only on a number of small experimental projects in the USA and UK. The system requires expensive specialist aggregates, skills and equipment, thus making it uneconomic on most projects. Whisper concrete is currently banned in new construction on UK trunk roads.

Figure 22.6. Whisper concrete.

A thin bituminous 35   mm wearing course is currently considered the most practical UK form of surface finish to this type of construction. The wearing course is held in place using a bituminous pad coat. The main concrete slab can then be constructed in non-air-entrained material.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780750656863503086

Real-scale applications of recycled aggregate concrete

Rui Vasco Silva , ... Jorge de Brito , in New Trends in Eco-efficient and Recycled Concrete, 2019

21.3.3 Section Interstate-10 in Houston (Texas), USA

Interstate 10 (I-10) is the major east-west Interstate Highway in Southern United States. In the US state of Texas, it runs east from Anthony, at the border with New Mexico, through El Paso, San Antonio and Houston to the border with Louisiana in Orange, Texas. In 1995, the Texas Department of Transportation began reconstruction in Houston in a section of IH-10 (9.3 km) with continuously reinforced concrete pavement (CRCP) made with coarse and fine RCA. Demolished concrete from the existing pavement was used. The original CRCP was constructed in 1968 and served heavy traffic for almost 30 years. A detailed study was conducted to evaluate the material properties of concrete containing RCA. The moisture control of the RA, especially fine aggregate, was critical in producing workable concrete.

The RAC exhibited lower density, compressive and indirect tensile strength than concrete with virgin aggregates. The densities of RAC ranged from 2.16 to 2.21   Mg/m3. The average compressive strength value was 31.8   MPa. The average indirect tensile strength value was 3.3   MPa. The modulus of elasticity was 18.8   GPa, much lower than that normally observed in conventional concrete and comparable to that of lightweight aggregate concrete. The coefficient of thermal expansion value ranged from 8.5 to 9.5   με/C. This value is comparable to that of concrete with virgin aggregates. The average sulphate value obtained is 1436   ppm and the average chloride content is 0.03   kg/m3. For the typical concrete mixes normally used in practice, the threshold chloride content to initiate corrosion is in the range of 0.6–0.9   kg/m3. The sulphate content was found to be comparable to that in concrete with virgin aggregates. The water absorption of RAC was much higher than that of concrete with natural virgin aggregates. This high water absorption of the RCA-containing concrete may not cause performance problems in the Houston area due to the mild weather conditions; however, in areas where freeze–thaw is prevalent, it may have an adverse effect on pavement performance. Ettringite deposits were found in the air voids in the old mortar of recycled coarse aggregates; however, these ettringite deposits do not seem to cause any damage to the surrounding concrete.

The field performance of the pavement was evaluated in terms of transverse crack spacing, crack widths, and spalling. The average crack spacing was 2.19   m. This crack spacing is larger than that of siliceous river gravel concrete and is comparable to that of limestone concrete. Low elastic modulus of concrete and good bond between coarse RA and the new mortar appear to be the key ingredients of good pavement performance. The large amount of old mortar in coarse RA does not appear to have an adverse effect on CRCP performance. After more than 10 years of service under heavy traffic, the CRCP section containing 100% RCA is still providing excellent performance with no single structural distress (Choi and Won, 2009).

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B978008102480500021X

Environmental Impact, Case Studies and Standards and Specifications

Ravindra K. Dhir OBE , ... Chao Qun Lye , in Sustainable Construction Materials, 2019

(c) Concrete Pavements

In concrete pavement applications, RA has been used as a replacement for NA in three conventional types of pavements, using joints, reinforcing steels or a combination of the two, as briefly described in the following:

•

Jointed plain concrete pavement (JPCP), made without reinforcement and may contain dowel bars and tie bars across transverse and longitudinal joints, respectively.

•

Jointed reinforced concrete pavement (JRCP), made with reinforcement and both dowel bars and tie bars across joints.

•

Continuously reinforced concrete pavement (CRCP), made with heavily reinforced concrete with no contraction joints.

Apart from these, RA has also been used in the concrete layer of composite pavements, which can be either (i) bituminous mix placed over concrete layer or (ii) a thin concrete layer placed over another concrete layer. In either case, the bottom layer can be jointed plain concrete or continuously reinforced concrete.

Case studies dealing with RA used in the construction of JPCP, JRCP, CRCP, composite pavements and other unspecified types of rigid pavements are given in Tables 13.10–13.14, respectively. In total, there are records of 63 road pavements containing RA worldwide since 1976, as noted in the following:

Table 13.10. Case studies involving the use of recycled aggregates in jointed plain concrete pavements

Reference Case Name Application Remarks
Year Country Joint Spacing Dowel RA (%) Max. Agg. Size Period
(a) Coarse RCA
American Concrete Pavement Association, 2010, 2015; Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 US 59, Worthington 1980 USA 4.0–4.9–4.3–5.8   m No 100 19   mm 14/26   years The pavement had performed well and was rehabilitated in 2004; in the 2006 survey, the pavement was in excellent condition
Hansen, 1986; Yrjanson, 1989 I-40, Oklahoma City 1983 USA 4.6   m — 100 — — Slip form paver was used
Cuttell et al., 1997, Gress et al., 2009, Wade et al., 1997, Sturtevant, 2007 & Yrjanson, 1989 I-94, Menomonie (WI 1) 1984 USA 3.7–4.0–5.8–5.5   m No, yes — 38   mm 10/22   years Although showing ASR expansion potential, the performance of RCA concrete was similar to that of reference
Dhir et al., 2003; Dhir et al., 2004; Dhir et al., 2011 Access road of biotechnology park a 2002 UK 5   m Yes 100 — 18   months Satisfactory performance
Nassar and Soroushian, 2016 Jackson Road, Ann Arbor a 2016 USA — — 100 — — Satisfactory performance
Smith et al., 2008; Smith, 2009;
Irali et al., 2013 		CPATT test road a 2007 Canada 3.7–4.5–4.0–4.3   m Yes 15, 30, 50 19   mm 2/5   years RCA sections were in good condition with performance similar to NA sections
Sadati and Khayat, 2014a; Sadati and Khayat, 2014b; Sadati and Khayat, 2016 Approach pavement of Stan Bridge a 2013 USA 4.5   m Yes 30, 40 25   mm 1   year The long-term deformation patterns and magnitude of RCA sections were similar to those of NA sections
(b) Mixed RCA (Coarse and Fine Fractions)
American Concrete Pavement Association, 2010, 2015; Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Snyder, 2016; Sturtevant, 2007 I-80, Pine Bluffs (WY 1) a 1985 USA 4.3–4.9–4.0–3.7   m No 65 coarse
22 fine		 25   mm 10/22   years Although showing ASR expansion potential, the field performance of RCA concrete was satisfactory
Cross et al., 1996; Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 K-7, Johnson County (KS 1) a 1985 USA 4.7   m No 100 coarse
25 fine		 38   mm 9/21   years The performance of RCA and NA sections was comparable
(c) Coarse RMA
Cavalline, 2012; Cavalline et al., 2014 Industrial roadway a 2011 USA 3.66   m Yes 100 — 11   months No cracks were observed on either RCA or NA section

—, data not available; ASR, alkali-silica reaction; NA, natural aggregate; RA, recycled aggregate; RCA, recycled concrete aggregate; RMA, recycled masonry aggregate.

a
NA section is available for comparison.

Table 13.11. Case studies involving the use of recycled aggregates in jointed reinforced concrete pavements

Reference Case Name Application Remarks
Year Country Joint Spacing Dowel RA (%) Max. Agg. Size Period
(a) Coarse RCA
Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 I-90, Beaver Creek (MN 2) 1984 USA 8.2   m Yes 100 19   mm 10   years Rapid deterioration of the transverse cracks occurred in RCA sections, but still in working condition
Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 US 52, near Zumbrota (MN 4) a 1984 USA 8.2   m Yes 100 25   mm 10/22   years RCA section showed more rapid deterioration than NA section
Yrjanson, 1989 I-94, Kalamazoo 1985 USA — — 100 — — n.a.
American Concrete Pavement Association, 2015 I-94, Paw Paw 1986–88 USA 2.5   m Yes — 19   mm 3   years Rapid deterioration of the pavements occurred, due to design and construction flaws associated with the use of RCA
Yrjanson, 1989 Lodge Freeway, Detroit 1986–87 USA — — — 19   mm — n.a.
Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 I-94, Brandon (MN 1) a 1988 USA 8.2   m Yes 100 19   mm 6/18   years Even through deteriorated faster than NA section, RCA section still provided good performance
(b) Mixed RCA
Bergren and Britson, 1977; Sturtevant, 2007; Yrjanson, 1989 US 75, Rock Rapids (IA 1) 1976 USA — — 35/50 coarse
16/30 fine		 38   mm 30   years Two RCA sections had transverse joint spalling at all the joints with most of them of low severity
Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 I-84, Waterbury (CT 1) a 1979 USA 12   m Yes 80 coarse
20 fine		 51   mm 14/26   years After 14   years of service, RCA and NA sections provided similar service, but both sections exhibited many high-severity transverse cracks in 2006 survey
McCarthy, 1985 I-94, Battle Creek 1983 USA — — 100 coarse up to 100 fine — — —
Hansen, 1995 I-94, Lawrence (MI 1) a 1984 USA 12.5   m Yes 100 coarse
30/50 fine		 — 11   years Fine RCA showed negative effects on the performance of concrete pavement
Yrjanson, 1989 I-94, Albion 1985 USA — — 100 coarse
30 fine		 — — Low pavement strength might be due to the use of fine RCA
Hansen, 1995 I-94, Galesburg 1985–86 USA 12.5   m Yes 100 — 9/10   years Good-quality RCA could possibly provide satisfactory performance

—, data not available; NA, natural aggregate; RA, recycled aggregate; RCA, recycled concrete aggregate.

a
NA section is available for comparison.

Table 13.12. Case studies involving the use of recycled aggregates in continuously reinforced concrete pavements

Reference Case Name Application Remarks
Year Country RA (%) Max. Agg. Size Period Crack Spacing
(a) Coarse RCA
Yrjanson, 1989 I-90 and I-94, Madison 1984 USA — 38   mm — — —
Cuttell et al., 1997; Gress et al., 2009; Wade et al., 1997; Sturtevant, 2007 I-90 Beloit (WI 2) 1986 USA — 38   mm 8/20   years 0.77/0.70   m Although showing ASR expansion potential, the field performance of RCA concrete was satisfactory
Yrjanson, 1989 I-35, Edmond 1988 USA — — —- —- —
(b) Mixed RCA
Roesler and Huntley, 2009; Roesler et al., 2011; Sturtevant, 2007 I-57, Effingham (IL 1) 1986–87 USA 100 coarse
35/36 fine		 38   mm 6/20   years 0.45   m RCA section had an average service life (23   years) similar to that of conventional CRCP within Illinois
American Concrete Pavement Association, 2010, 2015; Choi and Won, 2009; Snyder and Rodden, 2011; Snyder, 2016; TxDOT, 1998; Won, 2001 I-10, Houston 1995 USA 100 — 12   years 2.19   m Satisfactory performance, although with narrow crack widths and few minor spalls

—, data not available; ASR, alkali-silica reaction; CRCP, continuously reinforced concrete pavement; RA, recycled aggregate; RCA, recycled concrete aggregate.

Table 13.13. Case studies involving the use of recycled aggregates in composite pavements

Reference Case Name Application Remarks
Year Country Upper Layer Lower Layer RA (%) Max. Agg. Size Period
(a) Coarse RCA
Tompkins et al., 2009; Vancura et al., 2009 A93, Bavaria 1995–96 Germany NAC RCA
PCC		 100 — — The pavement had texture problems, but might not be relevant to the use of RCA
Hu et al., 2014; Rens et al., 2008, 2014 E34 Motorway a 2007–08 Belgium NAC RCA
PCC		 60 — 6   years Local crumbling was observed, associated with the phenomenon of horizontal cracking
Akkari and Izevbekhai, 2012; Darter et al., 2012 Cell 70, I-94 2010 USA HMA RCA
PCC		 50 38   mm — Satisfactory performance
Akkari and Izevbekhai, 2012; Darter et al., 2012 Cell 71, I-94 2010 USA EAC RCA
PCC		 50 38   mm — Satisfactory performance
Vancura et al., 2009 A27 Motorway — Germany — RCA
PCC		 — — — —
Vancura et al., 2009 A9 Motorway — Germany — RCA
PCC		 — — — —
(b) Mixed RCA
Bergren and Britson, 1977; Hu et al., 2014; Snyder, 2016; Sturtevant, 2007; Yrjanson, 1989 US 75, Rock Rapids 1976 USA RCA
PCC		 RCA and RAP
PCC		 60 RCA
40 RAP		 38   mm — Satisfactory performance, and still in use in 2016
Hu et al., 2014; Tompkins et al., 2009 A1 Motorway, near Eugendorf 1993–94 Austria EAC RCA
PCC		 — 32   mm 14   years The pavement had performed well in 14   years
Hu et al., 2014; Darter et al., 2012; Tompkins et al., 2009 A1 Motorway, near Traun 1994 Austria EAC RCA
PCC		 — 32   mm — Satisfactory performance
Hu et al., 2014; Tompkins et al., 2009 A1 Motorway, near Vorchdorf 1999 Austria EAC RCA
PCC		 — 32   mm — —
Tompkins et al., 2009; Darter et al., 2012 Section P, A93, Bavaria 2004 Germany NAC RCA
PCC		 — — — Satisfactory performance

—, data not available; CRCP, continuously reinforced concrete pavement; EAC, exposed aggregate concrete (natural aggregate); HMA, hot-mixed asphalt; NAC, natural aggregate concrete; PCC, Portland cement concrete; RA, recycled aggregate; RAP, reclaimed asphalt pavement; RCA, recycled concrete aggregate.

a
The pavement type was composite pavement and CRCP.

Table 13.14. Case studies involving the use of recycled aggregates in other types of concrete pavements

Reference Case Name Application Remarks
Year Country RA (%) Max. Agg. Size Period
(a) Coarse RCA
Anderson et al., 2009 RCA concrete pavements 1980s–1990s USA — — — n.a.
Reza and Wilde, 2017 Test sections, MN 1980s–1990s USA — — >20   years NA sections were more durable than RCA sections, nevertheless, the RCA test pavements performed satisfactorily
Reza and Wilde, 2017 US 59-U,
highway segment		 1980 USA — 19   mm >20   years No visible distresses were observed
Halm, 1983 Street road, Grand Rapids 1981 USA — — >20   years Satisfactory performance
Reza and Wilde, 2017 MN 15-U, highway segment 1984 USA — 19   mm >20   years No visible distresses were observed
Reza and Wilde, 2017 MN 60-D, highway segment 1987 USA — 19   mm >20   years No visible distresses were observed
Reza and Wilde, 2017 US 169-U, highway segment 1991 USA — 25   mm >20   years No visible distresses were observed
Reza and Wilde, 2017 MN 19, highway segment 1993 USA — 19   mm >20   years No visible distresses were observed
Reza and Wilde, 2017 US 169-U, highway segment 1994 USA — 19   mm >20   years No visible distresses were observed
Centre of Excellence for Airport Technology, 2016 Gate F7B, O'Hare Airport 2009 USA 100 — — RCA pavement was in good condition and did not experience high deformation
Cleary, 2013 Carpenter Street sidewalk 2011 USA 100 — 1   year No distress was observed in the pavement
Cleary, 2013 Concrete apron 2011 USA 100 — 1   year No distress was observed in the pavement
Cleary, 2013 Robinson Hall sidewalk 2011 USA 100 — 1   year No distress was observed in the pavement
Cleary, 2013 Wilson Hall pavement 2011 USA 100 — 1   year No distress was observed in the pavement
Rajab et al., 2014 C2 sidewalk, Ontario b 2013 Canada 10, 20, 30 20   mm 6   months No significant difference between RCA and NA sections
Halm, 1983 La Guardia Airport — USA — — — —
Hendriks, 1987 Test pavement near Helmond — Netherlands — — 4   years No damage caused by freeze–thaw actions was observed on the pavement
Koulouris et al., 2004 Industrial pavement, Day Group Ltd. — UK 30, 100 20   mm — The performance of RCA pavement was similar to that of NA pavement
Li, 2009; Shi et al., 2010 Concrete pavement, Shanghai — China 50 — >3   years Satisfactory performance
Yin et al., 2010 Test sections of G325 — China 60, 80, 100 31.5   mm 1   year The overall performance of RCA pavement was excellent, and no cracks were observed
Zhang and Ingham, 2010; Zhang et al., 2009 Residential driveway — New Zealand 100 — — The RCA concrete pavement was indistinguishable from NA pavement
(b) Mixed RCA (Coarse and Fine Fractions)
Yrjanson, 1989 I-680, Pottawattamie a 1977 USA — — — —
Iowa Department of Transportation, 1984; Yrjanson, 1989 Route 2, Taylor and Page County 1978–79 USA 100 coarse
40 fine		 38   mm 5   years Satisfactory performance
Gerarddu and Hendriks, 1985; Hendriks, 1987 Volkel Airfield pavement 1979 Netherlands 85–90 by vol. 31.5   mm — RCA mix was difficult to work with
Gerarddu and Hendriks, 1985; Hendriks, 1987 Taxiway, Maastricht Airport 1981 Netherlands 80 30   mm — The RCA mixture met the strength requirements
Rajab et al., 2014 C2 sidewalk, Ontario b 2013 Canada 20 20   mm 6   months No significant difference between RCA and NA sections

—, data not available; NA, natural aggregate; RA, recycled aggregate; RCA, recycled concrete aggregate.

a
The application type was pavement shoulder for that case study.
b
NA section is available to compare.
•

For JPCP, eight pavements were from the United States, built during the 1980s and the 2010s. Canada and the United Kingdom each had one built in the 2000s.

•

For JRCP, all 12 pavements were from the United States, built between 1976 and 1988.

•

For CRCP, all five pavements were from the United States, built between 1984 and 1995.

•

For composite pavements, of the 11 pavements, three were from the United States and the rest were from European countries (Australia, Belgium and Germany). Most of these pavements were built in the 1990s and 2000s.

•

For the unspecified type of rigid pavements, 17 of 25 case studies were from the United States, and the rest were from Canada, China, the Netherlands, New Zealand and the United Kingdom. Most of these pavements were built between the 1970s and 1990s.

Overall, except for one case in which RMA was used (Cavalline, 2012; Cavalline et al., 2014), RCA was the most commonly used RA in the concrete pavements. Nearly 70% of them were made with RCA in the coarse fraction, and the remainder was made with RCA in both coarse and fine fractions. The nominal maximum size of RCA used was normally between 19 and 38   mm. In most cases, coarse RCA was used to replace 100% of coarse NA in the concrete, and the others were between 35% and 80%.

Based on the available traffic data in one-third of the total case studies, it appears that the majority of the concrete pavements containing RCA had an average annual daily traffic (AADT) in the range of 7000–30,000 vehicles per day, with the lowest and highest AADT recorded being 2150 and 120,000 vehicles per day, respectively (Cavalline et al., 2014; Choi and Won, 2009; Hansen, 1995; Hu et al., 2014; Irali et al., 2013; Nassar and Soroushian, 2016; Darter et al., 2012; Rens et al., 2008; Reza and Wilde, 2017; Roesler and Huntley, 2009; Tompkins et al., 2009; Yrjanson, 1989; Wade et al., 1997). This suggests that concrete pavements made with RA had been tested for various traffic levels under real field conditions.

Core tests have been conducted to evaluate the in situ properties of RCA concrete pavements. The tested pavements normally had been in service for about 10 and 30   years. Where the results of both RCA concrete and NA concrete are available (American Concrete Pavement Association, 2010, 2015; Gress et al., 2009; Sturtevant, 2007; Sadati and Khayat, 2016; Nassar and Soroushian, 2016; Hansen, 1995), it generally appears that:

•

The compressive strength and tensile strength of the two concretes were about the same.

•

The static elastic modulus and dynamic elastic modulus of RCA concrete were lower than those of NA concrete.

•

The coefficient of thermal expansion of RCA concrete was higher than that of NA concrete.

In terms of field performance evaluation, falling weight deflectometer tests have been conducted in a number of case studies to assess the deflection property of the pavement and the load transfer efficiency (LTE) of its joints and cracks. For JPCP and JRCP, the joint LTE value of RCA concrete pavements was lower than that of reference NA concrete pavements, and on the other hand, the deflection of the RCA concrete pavements was higher (American Concrete Pavement Association, 2010; Cuttell et al., 1997; Gress et al., 2009). Only in two cases were the joint LTE and deflection values for RCA concrete pavements and NA concrete pavements found to be the same (Cuttell et al., 1997). For CRCP, although the comparison with NA concrete pavements was not available, the field results for the crack LTE and deflection of RCA concrete pavements suggested that the values obtained for RCA concrete pavements were within the expected values for NA concrete pavements (Cuttell et al., 1997; Roesler and Huntley, 2009).

Another important field performance evaluation was to examine the pavement distresses in terms of cracking, faulting (difference in elevation across the joint) and spalling (breakdown of the joint). The distress of RCA concrete used in three conventional pavement types, i.e., JPCP, JRCP and CRCP, has been investigated extensively. Although the results were mixed, it appears that RCA concrete pavements tend to show poor performance in cracking, which could affect the structural integrity of the pavement. On the other hand, the faulting and spalling behaviour of RCA concrete pavements was generally acceptable and comparable to that of NA concrete pavements.

Apart from structural adequacy, the ride quality of pavements is the other key performance indicator. The riding quality of concrete pavements made with RCA has been evaluated in terms of pavement serviceability rating (PSR) and IRI. The thresholds for PSR and IRI for classifying road quality as recommended by the US Federal Highway Administration (Arhin et al., 2015) are given inTable 13.15.

Table 13.15. Road quality based on pavement serviceability rating and international roughness index

Riding Quality PSR IRI, m/km
Good >3.5 <1.5
Acceptable 2.5–3.5 1.5–2.7

IRI, international roughness index; PSR, pavement serviceability rating.

Typically, concrete pavements made with RCA with less than 10   years of service had a PSR of about 4.0, indicating good riding quality (Gress et al., 2009; Smith et al., 2008; Irali et al., 2013; Sturtevant, 2007). However, the PSR for concrete pavements in service for 10 to 25   years was slightly reduced and varied in the range of 3.6–4.2, but still indicated good riding quality (Gress et al., 2009; American Concrete Pavement Association, 2015; Snyder, 2016; Stuartevant, 2007; Cuttell et al., 1997; Wade et al., 1997; Roesler and Huntley, 2009). In only a few cases did the PSR of RCA concrete pavements fall within 2.5–3.5, although the riding quality was considered acceptable (American Concrete Pavement Association, 2010, 2015; Gress et al., 2009).

In most cases, the IRI of RCA concrete pavements of service life up to 20   years was below 1.3   m/km, again suggesting good riding quality (Gress et al., 2009; American Concrete Pavement Association, 2015; Snyder, 2016; Stuartevant, 2007; Cuttell et al., 1997; Wade et al., 1997; Roesler and Huntley, 2009). Beyond 20   years of service, the IRI of the RCA concrete pavements tended to be about 1.8   m/km, falling into the category of acceptable riding quality (Cuttell et al., 1997; Roesler and Huntley, 2009).

Overall, it appears that the RCA concrete pavements can provide good riding quality and satisfactory performance for about 20   years of service life, beyond which the pavements might need to be rehabilitated.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780081009857000133

Asphalt Paving

James G. Speight PhD, DSC , in Asphalt Materials Science and Technology, 2016

10.2 Mix Design

Mix design is essential in order to enhance or mitigate the various roadway performance issues that are to be addressed and these issues include: (i) resistance to permanent deformation, (ii) resistance to fatigue and reflective cracking, (iii) resistance to low-temperature thermal cracking, (iv) durability, (v) resistance to moisture damage, (vi) workability, and (vii) skid resistance.

In order for an asphalt pavement to exhibit resistance to permanent deformation, the mix should not distort or displace under traffic loading, especially when the temperature is high (during summer) which causes the asphalt binder whereupon the traffic load is carried predominantly by the aggregate structure. Resistance to permanent deformation is controlled through improved aggregate properties (crushed faces), proper gradation, and proper asphalt grade and content.

Resistance to pavement fatigue and reflective cracking is inversely related to the stiffness of the roadway mix. Stiffer (harder) mixes are appropriate to deter the roadway from developing ruts, but focused design for rut resistance as the main property of the mix can be detrimental to the performance if the design allows pavement fatigue or reflective cracking. Stiff mixes perform more than adequately when used in thick hot mix asphalt pavements and when used as a thin overlay on a continuously reinforced concrete pavement. In addition, a thin hot mix asphalt mat placed on an unbound base or on a surface that is prone to reflective cracking (such as jointed rigid pavements and bound bases subject to shrinkage cracking) should use a mix that is designed for a balance between rut resistance and crack resistance. Proper selection of the asphalt binder can mitigate pavement fatigue and reflective cracking—another option for mitigating cracking is the inclusion of a specially designed crack-resistant interlayer in the roadway structure.

Low-temperature thermal cracking occurs in roadways that are subject to cooler temperatures and often occurs in areas where the differential between the daytime temperature and the night-time temperature is high. Thermal cracking can be mitigated by the selection of an asphalt binder with adequate low-temperature properties.

In order to exhibit in-service durability, the mix must contain sufficient asphalt binder to ensure an adequate film thickness of the blinder around the particles of the aggregate in order to minimize hardening and aging of the asphalt binder during production and also during in-service life. If the binder content is sufficient, this will also ensure adequate compaction in the field, keeping air voids within a range that minimizes permeability and aging.

The resistance to moisture damage (stripping) protects from the loss of adhesion between the aggregate surface and the asphalt binder, which has been assigned to deficiencies in the properties of the aggregate. However, the properties of the binder and the role of the binder properties in the asphalt–aggregate mix cannot be ignored (see Chapters 3 and 4 Chapter 3 Chapter 4 ). If it is assumed, during the design process, that moisture will eventually find a pathway into the pavement structure, the asphalt mix should be designed to resist stripping by (i) choice of a suitable binder, (ii) choice of a suitable aggregate, and (iii) selection, where necessary, of suitable anti-stripping agents.

Workability refers to the use of mixes that can be adequately compacted under laboratory conditions but which may not be easily compacted in the field. Too often laboratory data cannot be projected to performance of a product in the commercial world. In the case of an asphalt mix, adjustments may need to be made to the mix design to ensure the mix can be used in a roadway without sacrificing performance over the performance noted in the laboratory.

Finally, skid resistance relates to the need for an asphalt–aggregate mix to exhibit sufficient resistance to skidding, particularly under wet weather conditions. Aggregate properties such as texture, shape, size, and resistance to polish are all factors related to skid resistance. Many States have a wet accident reduction program (WARP) which is used to identify locations with high incidence of wet weather accidents and lower surface friction so the appropriate corrective measures can be taken. Under such a program, mineral aggregates are classified into four categories (such as a, b, c, or d) based on a combination of frictional and durability properties and the proper aggregate or blend may be selected to achieve the assessed skid-resistance rating.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128002735000106

A review on the best practices in concrete pavement design and materials in wet-freeze climates similar to Michigan

Naser P. Sharifi , ... Christopher Gilbertson , in Journal of Traffic and Transportation Engineering (English Edition), 2019

2.1 Continuously reinforced concrete pavement (CRCP)

As the name implies, CRCP uses continuous longitudinal reinforcement (typically 0.6%–0.7% cross-sectional area) to eliminate transverse contraction joints, instead of allowing the pavement to randomly crack transversely, with a typical crack spacing of 46–183 cm or 1.5–6 ft. The steel reinforcement holds the cracks tight, allowing aggregate interlock to transfer load across the crack interface. Typically, Grade 60 bars, which offer a minimum yield strength of 420 MPa or 60,000 psi, are used for the longitudinal steel reinforcement. The transverse steel is on chairs and is designed to support the longitudinal steel as well as restrain any longitudinal cracks that may form (Fig. 1). The main attractions of CRCP, if constructed properly, is its excellent ride quality (because it has no joint faulting), ability to be overlaid with asphalt without the risk of reflection cracking, and long life. Concrete pavements which are constructed in wet-freeze climates are subjected to harsh thermal stresses in addition to the traffic load-induced stresses. Furthermore, they are subjected to freeze-thaw deterioration mechanism. Thus, they are more vulnerable to initiation and propagation of different types of cracks in different directions. CRCP are equipped with rebar in two directions. The provided rebar could effectively control the propagation of both the longitudinal and transverse cracks; therefore, CRCPs seem to have promising performance in wet-freeze climates.

Fig. 1

Fig. 1. Continuously reinforced concrete pavement (not to scale) (Van Dam et al., 2015).

Major drawbacks of CRCP are its high initial construction cost, it is difficult to construct and it is costlier to repair than other pavement types. MDOT stopped using CRCP in 1978 and Louisiana stopped using CRCP in 1975 due to premature failures experienced in CRCP projects due to "insufficient thickness of the concrete slab, poor base, rounded aggregate, and/or poor construction technique, in addition to poor subgrade conditions" (Concrete Reinforcing Steel Institute, 2004; Michigan Department of Transportation, 2017a, b; Roesler et al., 2016). MDOT has performed but does not currently use CRCP, although they did some CRCP projects in the past. After reviewing the current state-of-the-practice, the research team recommends that MDOT reviews this practice and considers implementing this in the future. Louisiana has since resumed using CRCP in 2003 after assessing the successes from other states that are successfully using CRCP including Illinois and Texas (Concrete Reinforcing Steel Institute, 2004; Roesler et al., 2016). Michigan is considering the use of CRCP for a short section of pavement in Jackson to bridge over subsidence caused by a collapse of abandoned underground coal mines.

CRCP has been used for decades in the United States, in such states as California, Georgia, Illinois, Louisiana, North Dakota, Oklahoma, Oregon, South Dakota, Texas, and Virginia—some of which are not classified as wet-freeze climates. California, Illinois, and Texas are considered lead states in terms of usage, where CRCP is the design type of choice for heavily trafficked routes. The long-term pavement performance (LTPP) GPS-5 experiment demonstrated the longevity and overall good performance of CRCP (Federal Highway Administration, 2007). While Texas and California are not considered wet-freeze states, they both have a wealth of research, knowledge, and experience related to CRCP design and performance. California's mountainous regions, which experience freeze-thaw and considerable snowfall, have CRCP roads, most notably on I-5 in Northern California near the Oregon border (Plei and Tayabji, 2012). Overall, CRCP has shown very good performance and longevity.

The Illinois Department of Transportation has constructed CRCP on their freeway systems for nearly 65 years in a wet-freeze environment. The majority of the Chicago area urban interstates were originally constructed using CRCP and were reconstructed in the last decade using CRCP. Gharaibeh et al. (1999) provided a review of the design and performance of CRCP pavements in Illinois. The majority of the sections constructed between 1955 and 1994 were 18–25.5 cm or 7–10 in. thick (Gharaibeh et al., 1999). Just over half of these sections experienced D-cracking, a distress caused by freeze-thaw deterioration of coarse aggregate particles; other types of failures observed in the evaluation included punchouts, localized failures (potholes), existing repairs, and transverse cracks in which the steel had ruptured (Gharaibeh et al., 1999). Most failures were observed in 18 cm or 7 in. thick sections whereas the best performance was found in the 25.5 cm or 10 in. thick sections.

Recently, CRCP has been considered for use on the Illinois tollway (Tayabji et al., 2016). The Illinois tollway is located in the Chicago area, a wet-freeze area. The AASHTOWare Pavement ME Design software was used for the design, and the application included the use of an 8-cm or 3-in. thick flexible HMA base on granular subbase.

Due to the presence of the reinforcement (commonly 0.06%–0.07% in the longitudinal direction), CRCP comes with a higher initial cost than traditional jointed plain concrete pavement (JPCP). The construction of CRCP also requires greater care than JPCP and, thus, DOTs and local agencies may be reluctant to accept the technology due to the learning curve related to CRCP design and construction practices. Finally, even though CRCP typically requires less overall maintenance than JPCP, its maintenance techniques are costlier and require more specialization (Michigan Department of Transportation, 2017a, b). Overall, CRCP is a considered a cost-effective pavement type due to improved performance, longevity, and reduced life-cycle costs. Additionally, it has a superior performance in wet-freeze climates. Degradation because of repetitive freeze-thaw cycles is one of the main deterioration mechanisms of concrete pavements in wet-freeze climates. The expansion of penetrated water when it turns to ice makes the cracks bigger, and provides more room for extra water for the next freezing cycle. These cycles eventually cause the pavement to fail. However, CRCP takes the advantage of continuous rebar that prevents the cracking to expand.

Both the Illinois DOT and the Illinois tollway continue to make extensive use of CRCP in a wet-freeze region. Texas and California have both elected to use CRCP as their first choice for concrete pavement on heavily trafficked highways, including routes in California that would be considered wet-freeze. One of the main reasons for using CRCP is an expected service life in excess of 50 years.

Read full article

URL:

https://www.sciencedirect.com/science/article/pii/S2095756418303428

Use of recycled aggregates arising from construction and demolition waste in new construction applications

R.V. Silva , ... R.K. Dhir , in Journal of Cleaner Production, 2019

5.3 Section Interstate-10 in Houston, Texas, USA

The Interstate 10 (I-10) is one of the most important motorways in the southern part of the United States; it runs east from Anthony, through El Paso, to the border with Louisiana. In 1995, the Texas Department of Transportation started reconstruction of a 9.3 km section with continuously reinforced concrete pavement made with coarse and fine RCA from the existing pavement's concrete. The original pavement was built in 1968 and served heavy traffic for almost 30 years. A detailed study was conducted to evaluate concrete material properties containing RCA. The moisture control of the RA, especially fine aggregate, was critical in producing workable concrete.

The recycled aggregate concrete (RAC) exhibited lower density, compressive and indirect tensile strength when compared to that of control concrete. The densities of RAC ranged from 2.16 to 2.21 Mg/m3. The average 28-day compressive strength of the 15 cores taken from the pavement was of 31.8 MPa. The average indirect tensile strength value was 3.3 MPa. The modulus of elasticity was 18.8 GPa, much lower than that normally observed for normal concrete and comparable to that of lightweight aggregate concrete. The coefficient of thermal expansion value ranged from 8.5 to 9.5 με/C. This value is comparable to that of control concrete. The average sulphate value obtained was of 1436 ppm and the average chloride content was of 0.03 kg/m3. The sulphate content was comparable to that in the natural aggregate concrete. It was established that the high water absorption of the RCA-containing concrete, which was higher than that of the conventional concrete, would not cause performance problems in the mild weather conditions of the Houston area. Also, even though ettringite was observed in the coarse RCA' surface porous, it did not cause any damage to the concrete.

Field performance of the pavement was evaluated in terms of transverse crack spacing, crack widths, and spalling. The average crack spacing was of 2.19 m. This crack spacing was found to be larger than that of siliceous river gravel concrete but is comparable to that of limestone concrete. Low modulus of elasticity of RAC and the good adhesion between the coarse RCA and the new mortar were considered key factors for the pavement's good pavement. The large content of old adhered mortar in coarse RCA did not appear to have an adverse effect on the reinforced concrete pavement's performance. Furthermore, after 10 years of service under heavy traffic, the 100% RCA-containing reinforced concrete pavement section was still exhibiting excellent performance without any single structural distress (Choi and Won, 2009).

Read full article

URL:

https://www.sciencedirect.com/science/article/pii/S0959652619324795

Alternative materials for wearing course of concrete pavements: A critical review

Shreyas Pranav , ... Mukund Lahoti , in Construction and Building Materials, 2020

1 Introduction

Roads are the most widely availed means by which people and goods move around for specific purposes. This is so because roads offer door-to-door access. Based on the constituent materials, pavements have traditionally been classified into three major types, namely, concrete or rigid pavements, asphalt or flexible pavements, and composite pavements. Concrete pavement is typically made of Portland cement concrete (PCC), an asphalt pavement is made of hot mix asphalt (HMA) while a composite pavement is composed of both. Composite pavements are seldom used in construction because of the high costs and complicated analysis involved [1]. Flexible pavements account for about 83% of the total paved roads in the U.S. [2]. Nevertheless, the public concrete pavement length in the U.S., according to Table HM-12 in Highway Statistics 2017 published by the U.S. FHWA, for the year 2017 is 57,744 miles, which is sizeable. Similarly, in Japan, the concrete pavement length, according to Table 3 of the Road Statistics Annual Report (2017) [3] is 34,593 miles. Furthermore, Germany, Belgium and Switzerland have close to 20% of major roads made of concrete, and this percentage is steadily increasing [4] . France has been using concrete pavements for long, and it has 600 lane-kilometers of continuously reinforced concrete pavement [5]. The experience with concrete roads has been good in Sweden, although it still does not have a large proportion of concrete roads, because of conservatism. In addition, the Ministry of Road Transport and Highways (MoRTH) of India has chosen to construct all future National Highways in concrete by default, even though the initial construction cost is higher as compared to asphalt roads [6].

Flexible pavements have benefits such as low capital cost, high riding quality, and ease of construction. However, in the long run, when factors such as maintenance costs and vehicle operating costs are also considered, concrete pavements turn out to be more economical [7,8]. Concrete pavements are also preferred in certain scenarios owing to their being more durable and thereby facilitating longer design life. They also enable good visibility at night, and can be directly laid over poor soils. As a consequence, concrete pavements have found several specific applications. Many airports around the world rely on concrete pavements, especially where heavy aircraft are involved, and also for constructing the touchdown zone. It is desirable to use concrete pavements in situations where low maintenance is a requirement, such as the freeways that demand uninterrupted traffic flow.

Based on the BP Statistical Review of World Energy (2018) [9], the crude oil reserves are nearing exhaustion in about 50 years. It is therefore prudent to find an alternative to asphalt for pavement construction. Besides, concrete pavements have their challenges, such as low tensile strength, temperature susceptibility, non-biodegradability, the high initial cost of construction, and high greenhouse gas emissions [8]. In addition, it has been observed that concrete pavements often offer low riding quality, and that locally available cement and aggregates may not suffice the strength requirements of pavements. Recently, therefore, several innovative materials have been proposed for pavement construction. Moreover, when waste materials are used in pavements, it eases the landfill pressure and also cuts down the cost and the environmental impact involved in pavement construction. Many Departments of Transportation (DOTs) in the US, such as the Texas DOT, have initiated programs to promote the utilization of waste materials in pavement construction [10]. The Pradhan Mantri Gram Sadak Yojana (PMGSY) program in India, which has come up with technology initiatives for Indian rural roads, also devotes a major portion of its suggestions to promote the use of new technologies or materials in pavements.

Carrying out a state-of-the-art review on the utilization of alternative materials in concrete pavements can therefore be valuable for authoritative persons, professionals, researchers, and engineers aspiring to develop pavements using innovative materials that may be locally available. As per the knowledge of the authors, there have been minimal reviews on this topic. Bakash et al. [11] reviewed the feasibility of utilizing a few waste materials, namely, cement kiln dust, recycled asphalt shingles, construction and demolition materials, and recycled crushed brick in concrete pavements. It was based on changes in durability properties like compressive strength and splitting tensile strength of the mix. Yadav and Srivastava [12] reviewed the literature related to the use of fly ash and plastic waste in the use of concrete pavements. The present study aims to provide a more comprehensive review on the use of alternative materials in concrete pavements, incorporating a more extensive range of studies and materials. It is an effort to present the latest developments on this topic briefly. Further, it is important to note that the current article discusses the applicability of these alternative materials only for the wearing course of concrete pavements. Various alternative materials for base/sub-base layers have also been proposed in the literature, however, that discussion is beyond the scope of the current review article. The following sections discuss the mechanical properties desired of the wearing course of concrete pavements, alternative materials that may be used to substitute cement and aggregates, the effects of adding fibers to concrete pavements, and the scope for future work.

Read full article

URL:

https://www.sciencedirect.com/science/article/pii/S0950061819330612