Mechanical and Durability Properties of High Strength High Performance Concrete Incorporating Rice Husk Ash

Abstract

Nowadays, more infrastructure projects require concrete to have a high durability in addition to high strength. High strength high performance concrete (HSHPC) was developed to solve those problems. The weaknesses of HSHPC are high cost of constituent material such as silica fume which is mostly used as supplementary cementitious material (SCM), high cement content at low w/b, low workability and the need of specific curing regime. This research utilized rice husk ash (RHA) as the local waste material as an alternative to silica fume (SF). Five mixes of OPC concrete, 10%, 15% and 20% partial cement replacement by RHA, and 10% partial cement replacement by SF were chosen. The water/cementitious ratio adopted was 0.25 and the total cementitious materials content was 550 kg/m3. The mixing method adopted was the two-step mixing method. In addition to the development of compressive strength, workability, modulus of elasticity and the residue of compressive strength of concrete experienced immerse in 5% solution of magnesium sulphate were also reported. The specimens were cured and tested at 1, 3, 7, 28 and 56 days. Results show that concrete incorporating rice husk ash as 10% partial cement replacement and crushed granite as coarse aggregate with maximum size of 19 mm can achieve compressive strength as high as 110 MPa at 28 days under water curing regime. The HSHPC incorporating 10% RHA showed better overall performance than the HSHPC containing 10% silica fume and the control OPC.