scholarly journals Applications of Cement in Pavement Engineering

2020 ◽  
Author(s):  
Sarella Chakravarthi ◽  
Galipelli Raj Kumar ◽  
Sabavath Shankar
Keyword(s):  
Service Life ◽  
Recycled Concrete ◽  
Sustainable Construction ◽  
Concrete Aggregate ◽  
Recycled Materials ◽  
Pavement Rehabilitation ◽  
Reclaimed Asphalt ◽  
Pavement Engineering ◽  
Cement Stabilization

Recycled materials primarily Reclaimed Asphalt Pavement (RAP), and Recycled Concrete Aggregate (RCA) are produced from pavement rehabilitation and construction-demolition activities. Generally, these materials are utilized for landfills, parking lots, shoulders, and other places that are not environmentally friendly. The top layers of the pavement and concrete structures are constructed using superior qualities of aggregates that satisfy the specification. During their service life, the aggregates present in these structures undergo deterioration due to environmental and traffic factors. After reaching the end of their service life, the deteriorated structures are dismantled and considered as waste. Nevertheless, these recycled materials will have some retain value which can be used in different layers of the pavements in different percentages. The reuse of these materials in place of conventional aggregates preserves the environment and become a sustainable construction practice. Further, the direct utilization of these materials in the pavements may not satisfy the mechanical characteristics. To fulfill these gaps, cement stabilization of recycled materials is the best option. With this background, the proposed book chapter will highlight the usage of cement in pavement application, and a few types of research works carried in cement treated pavement layers will be discussed in a detailed and scientific manner.

scholarly journals Development of a Correlation between the Resilient Modulus and CBR Value for Granular Blends Containing Natural Aggregates and RAP/RCA Materials

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Muhammad Arshad
Keyword(s):  
Statistical Analysis ◽  
Resilient Modulus ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Triaxial Tests ◽  
Concrete Aggregate ◽  
Reclaimed Asphalt ◽  
Serviceable Life ◽  
Natural Aggregates ◽  
Repeated Load Triaxial

Limited supplies of natural aggregates for highway construction, in addition to increasing processing costs, time, and environmental concerns, have led to the use of various reclaimed/recycled materials. Reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) have prospective uses in substantial amounts in base and subbase layers of flexible pavement in order to overcome the increasing issue of a shortage of natural aggregates. This research presents the development of an empirical model for the estimation of resilient modulus value (MR) on the basis of CBR values using experimental results obtained for 52 remoulded granular samples containing natural aggregates, RCA, and RAP samples. Statistical analysis of the suggested model shows promising results in terms of its strength and significance when t-test was applied. Additionally, experimental results also show that MR value increases in conjunction with an increase in RAP contents, while the trend for the CBR value is the opposite. Statistical analysis of simulation results using PerRoad and KenPave demonstrates that addition of RAP contents in the subbase layer of flexible pavements significantly improves its performance when considering resistance against rutting and fatigue. However, results of repeated load triaxial tests show that residual accumulative strain under a certain range of loading conditions increases substantially due to the addition of RAP materials, which may be disadvantageous to the serviceable life of the whole pavement structure.

scholarly journals Desempenho de misturas asfálticas recicladas mornas e sua influência no dimensionamento do revestimento asfáltico

2020 ◽  
Vol 41 (2) ◽  
pp. 157
Author(s):  
Fernanda Gadler ◽  
Leonardo Fagundes Rosemback Miranda ◽  
Joe Villena
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Binder Content ◽  
Asphalt Mixtures ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Concrete Aggregate ◽  
Reclaimed Asphalt

The main purpose is to evaluate the performance of asphalt regarding resilient modulus and fatigue curve.The asphalt was produced with two wastes, reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA), using the technique of warm mixtures. The evaluation includes, based on these parameters, the thickness differences in the design of asphalt layer for each mixture. Five asphalt mixtures were produced with incorporation of RAP and RCA, in different gradation fractions (fine and/or course), without adding any natural aggregate. In view of the aim of the article, the mixtures were evaluated through tests of resilient modulus and fatigue life, in order to support the design, establishing the necessary thickness to meet traffic demands of each mixture. The design was performed using MeDiNa software. Among all results, it is highlighted that asphalt binder content is the component that exerts the greatest influence on the resilient modulus of the mixtures. As for fatigue, in addition to the binder content, the possible anchoring of the asphalt binder in the pores of the RCA may have favored the performance of the GARC_MRAP mixture. Still, all mixtures with RAP, both in fine or course fraction, resulted in lower coating thicknesses compared to the REF, for the same load request, with better performance of the GARC_MRAP mixture produced with 100 % waste material and incorporation of only 3.1 % neat binder.

scholarly journals Characteristics of the complex modulus of recycled cold mix with foamed bitumen and recycled concrete aggregate

2019 ◽  
Vol 262 ◽  
pp. 05002 ◽  
Author(s):  
Przemysław Buczyński ◽  
Marek Iwański
Keyword(s):  
Phase Angle ◽  
Complex Modulus ◽  
Asphalt Pavement ◽  
Recycled Concrete ◽  
Time Range ◽  
Concrete Aggregate ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Concrete Aggregate ◽  
Reclaimed Asphalt ◽  
Foamed Bitumen

This article presents research on recycled cold mix with foamed bitumen (MCAS) containing recycled concrete aggregate. The primary concept driving this research was to determine if recycled concrete aggregate (RC) could be used as a substitute for reclaimed asphalt pavement (RAP). Recycled concrete aggregate was used in the MCAS mix in amounts ranging from 20%, 60% and 80%. The reference mix was the MCAS mix containing 50% reclaimed asphalt pavement (RAP) and virgin aggregate. Identical 0/31.5-mm continuously graded dolomite virgin aggregate was used in all mixes. 2.5% foamed bitumen (FB) and 2.0% CEM I 42.5R Portland cement (PC) were used to increase the cohesion of the mineral mix. Foamed bitumen was produced from 50/70 penetration paving bitumen. The behaviour of the recycled base course was tested in the range of cyclic sinusoidal strain with amplitude εo = 25–50 με. The tests were carried out in the (-7°C, 5°C, 13°C, 25°C, 40°C) temperature and (0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz, 20 Hz) loading time range. The complex modulus was tested in a direct tension-compression test on cylindrical samples (DTC-CY) in accordance with EN 12697-26. The results of the tests were used to assess the complex modulus (E*), phase angle (φ) and complex modulus components (E1) and (E2).Tests of the mixes indicate that recycled concrete aggregate can be used in recycled cold mixes in amounts of up to 80%. Increasing the amount of recycled concrete aggregate does not cause excessive stiffness of the recycled mix in comparison with the reference mix. The tests did not demonstrate a significant difference in terms of the phase angle (φ), which indicates a similar content of the viscous part and elastic part in the obtained complex modulus for the reference mix (RAP + MCAS) and the mix containing recycled concrete aggregate (RC + MCAS).

Unsaturated properties of recycled concrete aggregate and reclaimed asphalt pavement

2013 ◽  
Vol 161 ◽  
pp. 44-54 ◽  
Author(s):  
Harianto Rahardjo ◽  
Alfrendo Satyanaga ◽  
Eng-Choon Leong ◽  
Jing-Yuan Wang
Keyword(s):  
Asphalt Pavement ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Concrete Aggregate ◽  
Reclaimed Asphalt

Total Recycled Asphalt Mixes: Characteristics and Field Performance

2019 ◽  
Vol 2673 (12) ◽  
pp. 149-162 ◽  
Author(s):  
Fazal R. Safi ◽  
Imad L. Al-Qadi ◽  
Kamal Hossain ◽  
Hasan Ozer
Keyword(s):  
Complex Modulus ◽  
Steel Slag ◽  
Field Performance ◽  
Recycled Concrete ◽  
Environmental Benefits ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Transverse Cracking

The use of recycled materials in asphalt concrete (AC) pavement has increased significantly because of their economic and environmental benefits. The use of recycled materials can pose risks to the performance of asphalt pavements, however. The Illinois Department of Transportation developed five total recycled asphalt (TRA) mixes in the pursuit of environmentally sustainable pavements. These mixes contain up to 60% asphalt binder replacement (ABR) obtained from reclaimed asphalt pavement (RAP) and recycled asphalt shingles. Virgin aggregates were replaced by 100% recycled aggregates including RAP, steel slag, and recycled concrete aggregate (RCA). Based on laboratory testing, all the mixes offered excellent rutting resistance because of their high ABR content. The TRA mixes were relatively less compliant and not very sensitive to field aging, whereas indirect tensile strength tests showed indistinguishable results. All mixes had comparable complex modulus |E*| and phase angle ([Formula: see text]) values at low temperatures. Laboratory-compacted specimens had relatively low flexibility index (FI) compared with field cores taken after construction. The FI values of the field cores decreased with aging, higher recycled materials content, or both. An exponential increase in transverse cracking was observed in the field cores because of their relatively high ABR, RCA/steel slag content, or both. The progression of field transverse cracking over time and FI values are well correlated. A three-dimensionally balanced mix design was introduced and used successfully to distinguish between AC mixes; it is proposed as a tool for better control mix designs and optimum field performance.

Utilization of Construction and Demolition Debris Under Traffic-Type Loading in Base and Subbase Applications

2000 ◽  
Vol 1714 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Thomas Bennert ◽  
Walter J. Papp ◽  
Ali Maher ◽  
Nenad Gucunski
Keyword(s):  
New Jersey ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Laboratory Test Results ◽  
Mixed Samples ◽  
Construction And Demolition Debris

As construction and remediation take place throughout New Jersey, the amount of construction and demolition debris increases, while the availability of landfill space decreases. A viable solution for disposing of these materials is to incorporate them into base and subbase applications. An extensive laboratory program was conducted on two types of construction and demolition debris: recycled concrete aggregate (RCA) and recycled asphalt pavement aggregate (RAP). These two materials were compared with dense-graded aggregate base coarse (DGABC), which currently is being used in roadway base applications in New Jersey. Both RCA and RAP were mixed at various percentages with the DGABC to evaluate whether an optimum mix blend could be formulated. The materials were evaluated under a traffic-type loading scheme that included resilient modulus and permanent deformation via cyclic triaxial testing. Laboratory tests indicated that the RAP, RCA, and DGABC blended materials all obtained higher resilient modulus values than the currently used DGABC. The permanent deformation results indicated that the RCA mixed samples obtained the lowest amount of permanent deformation when the material was cyclically loaded to 100,000 cycles. In contrast, the permanent deformation testing on RAP mixed samples resulted in the highest amount of permanent deformation at the same number of cycles. Existing models currently used for quarried base and subbase materials were used to predict the permanent deformation in the recycled materials. Laboratory test results indicated that these models could be used for predicting permanent deformation in unbound recycled materials.

scholarly journals Testing recycled concrete aggregate suffering different levels of alkali-silica reaction for use in new structures

2021 ◽  
Author(s):  
Matthew Piersanti
Keyword(s):  
Service Life ◽  
Recycled Concrete ◽  
Alkali Silica Reaction ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Construction Work ◽  
Supplementary Cementing Materials ◽  
New Construction ◽  
Land Space ◽  
Different Levels

As concrete reaches the end of its service life, it is demolished and placed in landfills, which is not sustainable as this consumes land space. Many demolished structures are crushed into recycled concrete aggregate (RCA) and used in new construction work to reduce concrete waste. To be used in concrete, the effects of RCA on the new structures should be carefully examined. The RCA studied in this research is an alkali-silica reactive gravel from Sudbury, Ontario. The RCA was obtained from different elements of a 20-year old bridge that suffered different levels of deterioration. It was determined that the level of deterioration that affected the previous structure does not significantly affect the expansion that will occur in the new structure. It was also determined that the expansion could be mitigated through the use of supplementary cementing materials although higher levels are required compared those required for the virgin aggregate.

scholarly journals Influence of Calcined Clay on the Strength Characteristics and Microstructure of Recycled Aggregate Concrete for Sustainable Construction

2021 ◽  
Vol 54 ◽  
pp. 56-70
Author(s):  
Oluwarotimi Michael Olofinnade ◽  
Isaac T. Oyawoye
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Sustainable Construction ◽  
Partial Replacement ◽  
Concrete Aggregate ◽  
Hardened Concrete ◽  
Conventional Concrete ◽  
Calcined Clay

Utilization of concrete wastes as aggregate in conventional concrete is regarded as a promising way of achieving sustainability within the built-up environment. This study investigated the performance of high strength concrete produced using recycled aggregate (RCA) with the addition of calcined clay in the concrete mixes. The recycled aggregate was sourced from concrete rubbles and treated by soaking in water, while calcined clay was sourced from the pilot pozzolana plant of the Nigerian Building and Road Research Institute (NBRRI). The recycled concrete aggregates were used as a replacement for coarse aggregate at levels of 0, 20, 40, 60, 80 and 100%, using a mix ratio of 1:1:2 at a constant water-binder ratio of 0.25. Superplasticizer was added to ensure the workability of the mixes. The calcined clay was added at 15 and 20% partial replacement for cement in the mixes. Physical and chemical properties of the materials used were determined, while the workability of the concrete mixes was examined using the slump. The compressive strength of the hardened concrete was determined after 7, 28 and 56 days of curing using 100 mm cube samples. Scanning Electron Microscope (SEM) was used to evaluate the morphology of selected concrete. Results showed that soaking of the recycled aggregate in water limit the water absorption rate of the RCA aggregates in the mixes, while the addition of calcined clay was observed to slightly reduce the workability of the concrete mixes. A reduction trend in compressive strength was noticed as the percentage of recycled aggregate increases, however, a significant increase in compressive strength was observed with the addition of calcined clay at 15% cement replacement. An optimum concrete mix containing 20% recycled aggregate and 15% calcined clay showed improve performance compare to the other mixes. The implication of these results suggests that recycled concrete aggregate can be used for the production of sustainable structural concrete.

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