An Experimental Study of Granular Material Using Recycled Concrete Waste for Pavement Roadbed Construction

Abstract

Rapid worldwide urbanization and drastic population growth have increased the demand for new road construction, which will cause a substantial amount of natural resources such as aggregates to be consumed. The use of recycled concrete aggregate could be one of the possible ways to offset the aggregate shortage problem and reduce environmental pollution. This paper reports an experimental study of unbound granular material using recycled concrete aggregate for pavement subbase construction. Five percentages of recycled concrete aggregate obtained from two different sources with an originally designed compressive strength of 20–30 MPa as well as 31–40 MPa at three particle size levels, i.e., coarse, fine, and extra fine, were tested for their properties, i.e., the optimum moisture content density, Californian bearing ratio, and resilient modulus. A characterization of the resilient modulus of the mixes under complex stress conditions was performed. The characterized modulus model was used in the nonlinear analysis of the pavement structure under traffic loading using KENALYER software. Consequently, the two critical responses, i.e., the tensile strain at the bottom of the asphalt layer and the vertical compressive strain at the top of the subgrade, were computed and compared for the pavement structures with varying types and percentages of recycled concrete aggregate used in the subbase layer.

Enhancing Asphalt Mixture Performance with Crumb Rubber: A Sustainable Solution for Improved Durability and Mechanical Properties

“…The conclusion reached: crumb rubber has a positive impact on Increasing Protection against Fatigue Crumb rubber is suitable because it can create a uniform mixture and prevent asphalt mixtures from settling due to its small particle size. Several studies show that adding crumb rubber to asphalt makes it work better, with less cracking and more fatigue life, strength, and resilience viscosity and adhesion [2][3][4][5][6][7][8][9]. The recycling of tires results in a cheaper product, crumb rubber CR which helps with the problem of solid waste management.…”

“…The recycling of tires results in a cheaper product, crumb rubber CR which helps with the problem of solid waste management. Over the past few years, numerous experimental studies have been conducted to assess and enhance the design philosophy, properties, specifications, and materials applied in asphalt rubber production [8,9].…”

Assessing and Predicting Geogrid Reduction Factors after Damage Induced by Dropping Recycled Aggregates

“…Designers must also consider essential parameters for a safe and economical design, strengthening its position as a desirable alternative [13]. In the past decades, in addition to the research evaluating the environmental and economic aspects related to using RCDW materials [20][21][22][23][24][25], several studies have reported the potential substitution of natural aggregates by RCDW materials in pavement layers [6,[26][27][28][29][30][31][32][33] and backfill material for geosynthetic reinforced structures [8,12,[34][35][36][37][38][39][40][41][42]. However, Delongui et al [26] emphasized that the RCDW characteristics are valid for the research's specific application conditions (e.g., type of CDW generated, recycling process).…”

Laboratory and Field Testbed Evaluation of the Performance of Recycled Asphalt Mixture Using High-Penetration Asphalt

“…The government also supports various policies to protect the environment; one measure is the recycling of waste asphalt concrete. This high-value-added resource uses the waste generated in the process of repairing old asphalt pavement roads [2][3][4]. Additionally, the development of sustainable asphalt mixtures containing recycled waste material such as fly-ash-based geopolymers and plastics also contributes greatly to green construction purposes [5,6].…”

“…In general, there are two main techniques used to recycle aged asphalt binders: rejuvenators and soft asphalt binders. The first method involves the use of rejuvenators, commonly called recycling agents [4]. This additive joins the mixing process and restores the virgin microstructure of an aged asphalt binder [11].…”