Characteristics of calcium silicate hydrate (C-S-H) reinforced bonding in retaining wall block incorporating cementitious material: RECO block
The Betoflor retaining wall blocks are dry-build mixtures of cement and aggregate with interlocking joint design to prevent displacement in horizontal and vertical directions. The retained soils merely through its self-weight without internal reinforcement provide an uncomplicated solution to withstand external subverting strength to earth and water retention. The hydration process between moisture and cement substantially liberates heat in retaining wall units and lead to rupturing after a significant period of exposure. Alternatively, this paper is presented to study the characteristics of partially reinforced cement using rice husk ash (RHA). The cementitious and pozzolanic natures of RHA are essential to enhance the durability in concrete and subsequently reduce the environmental impact. RHA is processed through burning of raw rice husk (RRH) at controlled temperature of 600C. Rice husk ash particulates replacement was set at 10%, 20%, 30%, 40% and for up to 50% by weight fraction. Compressive strength test was conducted to gauge the targeted strength performance of 30 ± 5N/mm2. Additionally, water absorption and corrosion resistance testing tested at 100 minutes time intervals and age of 1, 7, 14, 21 and 28 days of water curing respectively. The results indicated that replacement of 30% by weight fraction of RHA particulates postulates the optimum substitution value to obtain higher compressive strength, lower water absorption value and better resistance to deterioration by acidic attack. The crystal structure of calcium silicate hydrate (C-S-H) formation in the tested paste has significantly contributed to these enhanced properties.