Permeation Resistance of Sawdust Ash Blended Cement Laterized Concrete

Samuel Olufemi Folagbade,Aluko Olawale

doi:10.9744/ced.21.2.76-83

Abstract

This paper compared the initial surface absorption of conventional concrete and laterized concrete containing Portland cement (PC) and sawdust ash (SDA). Laterized concrete was produced at laterite contents of 15 and 30% as partial replacement for sand and SDA contents of 10 and 20% as partial replacement for PC. Compressive strengths at 28 days and initial surface absorption after 10 minutes (ISA-10) at 28, 60 and 90 days were determined at the water/cement ratios of 0.35, 0.50 and 0.65 and assessed at equal 28-day strengths of 25-35 N/mm2. At equal water/cement ratios, compressive strength reduced and ISA-10 increased with increasing content of laterite and SDA. On the other hand, compressive strength and resistance to surface absorption of the blended cement laterized concretes increased with increasing curing age. At equal strengths, all the blended cement laterized concretes have better resistance to surface absorption than the conventional PC concrete.

Highlights

Concrete is a widely used construction material
The initial surface absorption after 10 minutes (ISA10) at 28, 60 and 90 days were obtained in accordance with BS 1881-208 [31] using 150 mm concrete cubes oven-dried to constant mass at 105±5oC
Based on the foregoing, a percentage replacement of Portland cement (PC) with sawdust ash (SDA) resulted in an initial surface absorption after 10 minutes (ISA-10) increase of 0.89% for conventional concrete and 0.630.67% for laterized concrete

Summary

Introduction

Concrete is a widely used construction material. The need to prevent the depletion of non-renewable materials and make concrete construction sustainable led to the replacement of the constituent materials of concrete with alternative ones. The higher content of fine particles in laterite would result in higher specific surface and higher quantity of cement needed to properly coat the soil particles and ensure adequate hydration reaction within the matrix of the concrete. From the foregoing, the combination of SDA and laterite as partial replacements for Portland cement and sand contents of concrete respectively would make concrete cheaper, more environmentally compatible and possibly more durable than the conventional concrete where laterite is abundant. In order to provide more information on the durability of SDA blended cement laterized concrete, this paper investigated the initial surface absorption after 10 minutes (ISA-10) of this concrete, at different water/cement ratios and 28-day compressive strengths, with a view to providing more information on its permeation resistance and suitability for construction. The initial surface absorption after 10 minutes could be used to sufficiently assess the ability of concrete to provide protection for its embedded reinforcing steel [31] and, possibly, wall finishes

Materials and Methods

Analysis and Discussion of Results

18. BS EN 206-1

Findings

36. BS EN 12390-3