Strength of Concrete Using Different Types of Additives

Abstract

In this investigation, conventional concrete mixes (as a reference mixes) and concretemixes produced with (5, 10, and 20)% of cement replacement by silica fume, crushed glass and crushed nucleate additives respectively, these mixes were used in preparing (144) concrete specimens. Laboratory test results in dictated that:

a)There was a significant increase (17.6 to 88.5 and 8.8 to 25.8) % in the compressive strength of concretes produced with silica fume and crushed glass additives respectively, while a significant reduction (29.6 to 62.6)% in the compressive strength was recorded using concrete mixes with crushed nucleate.
b)there lation ships between the 7-day(fc,7)and:the28day(fc,28)compressive strength areas follows
- [fc,28 = 1.701 fc,7] for (reference mix);
- [fc,28 = (1.590 to 1.931) fc,7] for silica fume mixes;
- [fc,28 = (1.660 to 1.813) fc,7] for crushed glass mixes;
- [fc,28 = (1.521 to 1.796) fc,7] for crushed nucleate mixes.
c)percentages of increasing in both flexural and splitting tensile strengths, as compared with conventional concrete, are as follows:
- for silica fume mixes: (26.92 to 48.72 and 44.44 to 72.22)% respectively;
- for crushed glass mixes: (46.15 to 71.79 and 11.11 to 36.11)% respectively.
On the other hand, crushed nucleate mixes recorded a drop in both flexural and splitting tensile strengths (5.41 to 34.48 and 28.57 to 71.43)% respectively.
d)Finally, the research included also deriving different relationships between compressive, flexural and tensile strengths of concretes produced using silica fume and crushed glass additives.