COMPARATIVE RESPONSE OF SBR LATEX MODIFIED CONCRETE

摘要

Behaviour of SBR (Styrene-Butadiene Rubber) Latex modified concrete in comparison to normal concrete having same mix proportions, aggregates, net water-cement ratio and similar curing conditions has been studied in both short and long terms. Short-term studies were conducted up to the age of 28 days during which the specimens were subjected to three different curing methods. After that period the remaining specimens were kept in the laboratory and underwent similar temperature and relative humidity variations. At the age of two years, specimens were again tested for strength, concrete microstructure using Olympus PME-3 inverted metallurgical microscope and SEM, pores and their distributions and chemical resistance against acids and salt solutions. The specimens for these tests were obtained by cutting half the original 100x100x100mm specimens. The results indicate that although the compressive strength of SBR modified concrete reduces in comparison to normal concrete, the durability and performance of modified concrete is certainly enhanced. It was indicated that there should be sufficient cement-sand paste around the lime stone coarse aggregates in order to improve the chemical resistance of concretes.