COMPARATIVE EVALUATION OF THE FLEXURAL STRENGTH OF CONCRETE AND COLCRETE

Abstract

Colcrete is a construction material resulting from grouting of prep laced coarse aggregates with colgrout. Colcrete is more economical to use than concrete. If the performance of colcrete in service is favourably comparable to that of concrete, some construction costs could be saved in the use of colcrete in place of concrete. This paper reports the findings of a study carried out to compare the flexural strength of colcrete to that of concrete. Concrete beams of 750 mm × 150 mm × 150 mm were cast in accordance to BS 1881: Part 118: 1983 using 1:2:4 and 1:3:6 nominal mix ratios, with water-cement ratios of 0.56 and 0.58, respectively. Similar colcrete beams were cast using 1:2 and 1:3 colgrout with 0.56 and 0.58 water cement ratios, respectively. Three different sizes - 47 mm, 50 mm, and 55 mm - of coarse aggregates were used. The beams were tested for flexural strength after 28 days of casting and curing in water. Flexural strength results for the concrete and colcrete were compared. Results show that for the two mix ratios investigated, and the three types of coarse aggregates used, the flexural strength of colcrete is higher than that of concrete. On the basis of this study, it is concluded that colcrete performs better in flexure than concrete. The use of colcrete is, therefore, recommended in structures, especially members predominantly loaded in flexure, so as to reap the benefits of better performance and cost savings in construction projects.