Strength Prediction Model for Accelerated Cured Fly-Ash Based Concrete

Abstract

The most important property of concrete is its compressive strength, which is carried out after 28-days proper curing of concrete. This test is affected by other factors like the condition of curing, water to cement ratio, method of transportation, handling of the concrete, extent of vibrations and quality of the ingredients of mix proportion. This research study is an attempt to develop a simple Mathematical equation also known as mathematical model, by using linear regression analysis to estimate the 28-day fc’ (Compressive Strength) of concrete from the test results carried out atearly age. This simple linear equation develops a relationship of 28.5 hours accelerated cured compressive strength with normal cured compressive strength after 28-days. These results show that most of the predicted values of compressive strength, calculated via equations, lies within permissible range difference for compressive strength achieved by experimental method, which is clear indication of credibility of the equations obtained for compressive strength at different age of concrete. The results showed that compressive strength of concrete increases with the increase in content of FA (Fly Ash) upto 30% replacement, and the compressive strength of the concrete starts decreasing beyond 30% FA substitution. This argument is totally in line with all the literature carried out for this research.

Empirical Equation for Concrete Made With PPC or OPC with Fly Ash by Accelerated Mix Design Method

“…Many parameters affect the strength of concrete such as quantum of fly ash, quality and quantity of binder material, aggregate size, curing regime, chemical effect, concrete grade used and mix proportions. Hydration itself is affected by the temperature (Khan et al, 2019;Krishna et al, 2010). To accelerate the strength gain at early age and to relate it to the 28-days compressive strength, proper trend lines and calibration curves are needed.…”