Behavior of a hot mix asphalt made with recycled concrete aggregate and crumb rubber

2019 ◽  
Vol 46 (6) ◽  
pp. 544-551 ◽  
Author(s):  
Marcio Muniz de Farias ◽  
Ferney Quiñonez Sinisterra ◽  
Hugo Alexander Rondón Quintana

An experimental program was devised to evaluate the effect on the resistance of a hot mix asphalt, due to the total replacement of a natural aggregate (limestone — LS) by a recycled concrete aggregate (RCA). Two asphalt binders were used: conventional AC 50-70 (penetration grade) and AC 50-70 modified with crumb rubber (CRM). The mechanical properties investigated were the stability and flow ratio (Marshall test), indirect tensile strength, resistance to abrasion (Cantabro test), resilient modulus, resistance to permanent deformation, to fatigue and to moisture damage (modified Lottman test). When the LS is completely replaced by RCA, the resistance under monotonic loading, moisture damage and permanent deformation improved, the mass loss in the Cantabro test and the resilient modulus shows appropriate values, however, the fatigue resistance decreases. Besides, mixtures with RCA using CRM binder showed lower fatigue life under stress controlled tests, but much better rutting resistance.

Author(s):  
Burcu Aytekin ◽  
Ali Mardani-Aghabaglou

In this paper, a comprehensive literature review was conducted on the utilization of recycled concrete aggregate (RCA), which is the dominant construction and demolition waste material, in base and subbase layers and its comparison with natural aggregate (NA). The effects of crushing on the particles as a result of the compaction on the resilient modulus, permanent deformation, and California Bearing Ratio are analyzed. The paper also contains the NA consumption and waste disposal policies of different countries, RCA standards, and the environmental-economic reasons for its use. This literature review mainly focuses on pavement layers as this is the main application of RCA in the use of recycled materials. Developing integrated construction and demolition waste management will help achieve the primary goal of preventing and reducing the generation of these wastes, both locally and globally. In this way, not only is the main purpose of preventing the increase in the production of construction and demolition waste achieved, but also the reuse and recycling of the waste materials produced are encouraged. Results show that RCA has equivalent or better performance than virgin aggregate for almost any application with proper care and process control, and can be used in unbound pavement layers or other applications requiring compaction. But it is always recommended that its mechanical properties and durability performance be evaluated with full-scale tests before use. The information provided will be useful for contractors and engineers to evaluate alternative solutions and to explore the rational use of such sustainable materials in applications.


2021 ◽  
Vol 13 (8) ◽  
pp. 4245
Author(s):  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Wojciech Sas

The construction sector is currently struggling with the reuse of waste originating from the demolition and modernization of buildings and roads. Furthermore, old buildings are gradually being replaced by new structures. This brings a significant increase of concrete debris to waste landfills. To prevent this, many studies on the possibilities of recycling concrete, known as recycled concrete aggregate (RCA), have been done. To broaden the applicability of reused concrete, an understanding of its properties and engineering behavior is required. A difficulty in sustainable, proper management of RCA is the shortage of appropriate test results necessary to assess its utility. For this reason, in the present study, the physical, deformation, and stiffness properties of RCA with gravely grain distribution were analyzed carefully in the geotechnical laboratory. To examine the mentioned properties, an extensive experimental program was planned, which included the following studies: granulometric analysis, Proctor and oedometer tests, as well as resonant column tests. The obtained research results show that RCA has lower values of deformation and stiffness parameters than natural aggregates. However, after applying in oedometer apparatus repetitive cycles of loading/unloading/reloading, some significant improvement in the values of the parameters studied was noticed, most likely due to susceptibility to static compaction. Moreover, some critical reduction in the range of linear response of RCA to dynamic loading was observed.


2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.


2020 ◽  
Vol 41 (2) ◽  
pp. 157
Author(s):  
Fernanda Gadler ◽  
Leonardo Fagundes Rosemback Miranda ◽  
Joe Villena

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.


2019 ◽  
Vol 221 ◽  
pp. 469-479 ◽  
Author(s):  
Jianmin Ma ◽  
Daquan Sun ◽  
Qi Pang ◽  
Guoqiang Sun ◽  
Mingjun Hu ◽  
...  

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