TY - JOUR A2 - Zhou, Yuanxin AU - Ngui Musyimi, Festus AU - Wachira, Jackson Muthengia AU - Thiong’o, Joseph Karanja AU - Marangu, Joseph Mwiti PY - 2019 DA - 2019/11/03 TI - Performance of Ground Clay Brick Mortars in Simulated Chloride and Sulphate Media SP - 6430868 VL - 2019 AB - The durability of cement-based structures majorly depends on their resistivity to the aggressive media in the construction environment. The most aggressive ions commonly encountered in construction environment are chloride (Cl) and sulphate (SO42). The interactions of these ions with hydrated cement influence their durability and ultimate service life. This paper reports the experimental findings on an investigation on the diffusivity of Cl and SO42 ions into mortars made from two mixtures: one made from ground calcined clay bricks (GB) and commercial ordinary Portland cement (OPC) and the other consisting of GB and Portland pozzolana cement (PPC). The test media were 3.5% Cl and 1.75% SO42 solutions. For comparison, commercial OPC and PPC were also investigated. GB was blended with OPC at replacement levels of 25, 35, 45, and 50% to make OPCGB. Similar blends were also made with PPC replacement levels of 15, 20, and 25% to make PPCGB. Mortar prisms measuring 160 mm × 40 mm × 40 mm were cast at the water-to-cement ratios (w/c) of 0.40, 0.50, and 0.60 using each category of cement and cured in water for 3, 7, and 28 days. Compressive strength measurements were taken at each of the curing ages. The 28-day cured mortar prisms were subjected to compressive strength analysis and accelerated Cl and SO42 ingress for 36 hours at 12 V. Ion profiling was done on the mortars, and diffusion coefficients of the Cl and SO42 ions were approximated. The results showed that there was an increase in compressive strength after exposure to Cl and SO42 ions. In addition, the ingress of Cl and SO42 ions decreased with an increase in depth of cover. Blended cement exhibited lower Cl and SO42 ingress than OPC. The ingress of Cl was observed to be higher than that of SO42 ions. The ingress of Cl and SO42 ions increased with an increase in w/c ratio. The results further showed that there was a drop in the ingress of Cl and SO42 ions with an increase in replacement up to 35 percent for OPC. A 15 percent replacement showed a better compressive strength development compared with 20 and 25 percent replacement for PPC. Blended cement showed lower apparent diffusion coefficients (Dapp) compared with OPC. PPC, OPCGB-35, and PPCGB-15 exhibited similar performance in terms of strength development, aggressive ions ingress, and Dapp. In conclusion, it was found that the test cements, PPCGB-15 and OPCGB-35, can be used in similar tested environments as commercial PPC. SN - 2314-4904 UR - https://doi.org/10.1155/2019/6430868 DO - 10.1155/2019/6430868 JF - Journal of Engineering PB - Hindawi KW - ER -