Sustainable Construction – Use of Blended Cements in High-Performance Concrete Pavements

Abstract

This study aimed at evaluating the properties of high performance concrete pavements made from blended cements using agricultural wastes i.e. rice husk ash, Portland cement, natural aggregates and sand. Large quantities of agricultural wastes like rice husk are generated from rice processing units worldwide. Rice husk ash blended with Portland cement has proved to improve cement strength as well as durability however its use in high performance concrete pavements has not been investigated to-date. Keeping in view the typical problems of pavements mainly due to dynamic loading, larger exposed surfaces, use of deicing chemicals, effects of groundwater containing sulphates etc, wide ranging investigations covering most aspects of mechanical behavior, permeability and durability aspects including sulphate and chloride resistance and shrinkage were carried out for various mixes for compressive strengths of 60N/mm2 and 80N/mm2. Compressive strengths of concrete specimen with blended cements were observed to be higher by about 5 to 10% than the control specimen, higher values for concrete with 75% Portland cement blended with 25% rice husk ash whilst lower values correspond to concrete with 50% Portland cement blended with 50% rice husk ash. Similarly, higher flexural strength, improved moduli of elasticity, higher density, lower permeability, improved sulphate and chloride resistance and reduced shrinkage were observed. Better strengths and improved durability of such pavement concretes is likely to make it a more acceptable material for major road construction projects.