Influence of field recycled coarse aggregate on properties of concrete

• Published in: Materials and structures Vol. 44; no. 1; pp. 205 - 220
• Main Authors: Chakradhara Rao, M., Bhattacharyya, S. K., Barai, S. V.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.01.2011; Springer; Springer Nature B.V
• Subjects: Aggregates and other concrete constituents; Applied sciences; Artificial aggregates; Building construction; Building Materials; Buildings. Public works; Cement concrete constituents; Civil Engineering; Concretes. Mortars. Grouts; Engineering; Exact sciences and technology; General (composition, classification, performance, standards, patents, etc.); Machines; Manufacturing; Materials; Materials Science; Original Article; Processes; Recovery materials; Solid Mechanics; Theoretical and Applied Mechanics; Coarse aggregate replacement ratio (CRR); Compressive strength; Chloride penetration; Ultrasonic pulse velocity (UPV); Volume of voids; Recycled aggregate concrete (RAC); Construction materials; Concrete mix design; Durability; Void fraction; Experimental study; Fresh concrete; Chlorides; Coarse aggregate; Properties of materials; Water absorption; Hardened concrete; Recycled material; Ultrasonic method
• ISSN: 1359-5997; 1871-6873
• DOI: 10.1617/s11527-010-9620-x

This paper investigates the influence of different amounts of recycled coarse aggregates obtained from a demolished RCC culvert 15 years old on the properties of recycled aggregate concrete (RAC). A new term called “coarse aggregate replacement ratio (CRR)” is introduced and is defined as the ratio of weight of recycled coarse aggregate to the total weight of coarse aggregate in a concrete mix. To analyze the behaviour of concrete in both the fresh and hardened state, a coarse aggregate replacement ratio of 0, 0.25, 0.50 and 1.0 are adopted in the concrete mixes. The properties namely compressive and indirect tensile strengths, modulus of elasticity, water absorption, volume of voids, density of hardened concrete and depth of chloride penetration are studied. From the experimental results it is observed that the concrete cured in air after 7 days of wet curing shows better strength than concrete cured completely under water for 28 days for all coarse aggregate replacement ratios. The volume of voids and water absorption of recycled aggregate concrete are 2.61 and 1.82% higher than those of normal concrete due to the high absorption capacity of old mortar adhered to recycled aggregates. The relationships among compressive strength, tensile strengths and modulus of elasticity are developed and verified with the models reported in the literature for both normal and recycled aggregate concrete. In addition, the non-destructive testing parameters such as rebound number and UPV (Ultrasonic pulse velocity) are reported. The study demonstrates the potential use of field recycled coarse aggregates (RCA) in concrete.