Flexural and Split Tensile Strength Properties of Lime Cement Concrete

This paper investigated the flexural strength and split tensile strength properties of hydrated lime cement concrete. Ordinary portland cement was partially replaced by hydrated lime at varying percentages ranging from 5% to 30%. Concrete under study was made of ordinary portland cement (OPC), hydrated lime, river sand, granite chippings and water. The test specimen were prototype concrete beams of sizes 150x150x600mm and concrete cylinders of dimensions 150x300mm. Three concrete specimens were cast for each mix ratio considered, and cured in open water tanks for 7, 14, 21, and 28 days for the beams, and cylinders respectively. Since there were 30 different mix proportions considered, a total of 360 concrete prototype beams, and 360 concrete cylinders were produced and cured before testing in tension. Maximum design strength recorded in flexure at 7, 14, 21 and 28 days were 3.08N/mm2, 3.580N/mm2, 4.910N/mm2 and 5.03N/mm2 respectively, while those recorded in splitting were 1.565N/mm2, 2.350N/mm2, 3.605N/mm2, and 3.725N/mm2respectively. It was observed that tensile strength values from the flexural test gave higher values than those of the split tensile test. Strength properties increased with curing age. Optimum replacement of OPC with hydrated at 28 days curing age was observed at 13.83% for both properties. Optimum mix ratio for the two properties studied was 0.863:0.138:2.625:5.250 at a water cement ratio of 0.58. Hydrated lime cement concrete can be used effectively for structural works at curing age of 28 days and beyond