Impact of Different Accelerating Admixtures and Accelerated Curing Conditions on Strength of Concrete

The present experimental work explains the combined effect of a accelerator method of curing and chemical in the strength development of concrete. Ordinary Portland cement (OPC) was used to produce concrete mixtures. Concrete mixtures were designed as per the guidelines of IS 10262:2009. Compressive strength of standard cube specimens (150 mm) at early and later- age, cured with water were studied. Performance of accelerator at a given age of concrete was assessed based on the maximum percentage increase in the compressive strength. The strength of control mix cured with water is taken as reference. Among various types of chemical admixtures, Non Chloride Accelerator Admixture (NCA) is chosen. The non-chloride accelerator admixture is added with normal mix of the concrete in the nominal dosage and the effects are studied. 0.5%, 1.0%, 1.2% of non-chloride accelerators were mixed with M20 grade of concrete. The optimum level of high early development strength was analyzed. Average efficiency of the curing compound for the given age was calculated as the ratio of average compressive strength of concrete cured with NCA to that cured with water. The test results revealed that, the type of curing affected the optimum performance of accelerator in concrete mixtures. Average efficiency of the curing compound was found to be more at early- age of the concrete mixtures. Sodium hydroxide (NaOH) generally known as caustic soda are used as water proofing compound. NaOH and cement is used to seal the leakage in RCC water tank, within one hour of application it forms a solid watertight compound and its strengths are also more than the normal cement. The additive chemical in concrete mixture will increase the hydroxyl ions, which increases its performance. Fibre reinforce polymers (Recron-3S)reinforcing the microstructure of the concrete which increase the strength of concrete .another technique to get the early strength is accelerated curing condition .if we add both the techniques definitely the higher strength would be achieved at short period. Use of calcium chloride (CaCl2) accelerates the hydration process in concrete due to the calcium react with silica.