Prediction Model of Compressive Strength of Concrete Composed of Portland Composite Cement, Marine Sand, and Sea Water Using Maturity Method

The utilization of portland composite cement, marine sand and sea water lead to concrete production more economical in the remote island, both in terms of time and cost. The prediction of concrete compressive strength in Indonesia has been provided in SNI 03-2834-2000. This code is used for predicting the compressive strength development of normal concrete with used ordinary Portland cement. This paper presents the predicted result of concrete compressive strength at ages of 28 and 90 days based on the compressive strength data and time-temperature factor at age of 1 and 2 days and provides a mathematical model to determine the coefficient of compressive strength development prediction. The cylindrical specimens were prepared with a mixture of Portland composite cement, marine sand, and sea water under closed room curing that is kept at a constant temperature of 25°C and the humidity of 70±1%. At prediction based on early age 1 day compressive strength, comparison between the actual compressive strength and the predicted compressive strength shows the difference value were 0.6% and 0.2% for 28 and 90 days compressive strength, respectively. At prediction based on early age 2 days compressive strength, comparison between the actual compressive strength and the predicted compressive strength shows the difference value were 2.2% and 1.5% for 28 and 90 days compressive strength, respectively.