EFFECT OF COARSE/FINE AGGREGATE RATIO AND CEMENT MATRIX STRENGTH ON FRACTURE PARAMETERS OF CONCRETE

The effect of aggregate combination(the ratio of fine aggregate to the sum of fine and coarse aggregates in weight from 0.30 to 0.67)and matrix strength(compressive strength from 40 to 80MPa)on the fracture parameters, including tensile strength, flexural strength, stress-crack width(σ-w)relationship as well as fracture energy are evaluated from three point bending test results by means of fictitious crack model based analyses. The results show that for a constant total aggregate amount, the compressive strength is almost not influenced by varying the coarse aggregate content. Tensile strength, flexural strength as well as fracture energy determined from the(σ-w)relation can be enhanced by adding more coarse aggregate. However, the above enhancement is gradually reduced with the increase of matrix compressive strength.