Enhancement of deformation constant and mechanical properties of concrete using additive materials

摘要

The deformation of two bodies touching at one or more points due to collision is based on dynamic loading, and as such, these impacts are very important in dynamic analysis to find the force time history as developed during tests. The deformation constants for the contact surface between a freely dropped steel mass and concrete containing additives used to increase the compressive strength and enhance other mechanical properties such as tensile strength and to produce new concretes such as reactive powder concrete with and without steel plate covers of different thicknesses on the top face of the specimens are investigated. The mechanical properties of reactive powder concrete, including compressive strength, tensile strength, and modulus of rupture, are also explored and compared with those of normal weight concrete with different percentages (12, 15, 20 and 25% by weight) of silica fume. The characteristics of the micro steel fibre mixed with concrete in this investigation are 15 mm length, 0.2 mm diameter, with aspect ratios of 75, added as 1, 1.5 and 2% by volume, while the water cement ratios used are 20 and 22%. All specimens were tested at 7 and 28 days, and results for the deformation constant and mechanical properties at those ages are discussed. A mathematical model is suggested to express compressive strength as a function of percentages of steel fibre, and further mathematical models are suggested for splitting tensile strength and flexural strength as functions of compressive strength based on these experimental tests. The suggested mathematical models were compared with results from other researchers; close agreement of the test results of the present study and other researchers' work were found.