Production of self-compacting concrete containing limestone powder with the effect of internal and external salts

Abstract

This study aims at investigating the influence of different amounts of internal sulphate (CaSO4) and external salts on the properties of Self-Compacting Concrete (SCC). Three sets of mixes (No.1), (No.2) and (No.3) which are reference mix, mixes with internal sulphate and mixes exposed to external salts respectively are designed with the same mix proportion and maximum size of aggregate 10 mm. In order to determine the selfcompacting concrete, different tests are adopted such as Slump flow, V-funnel, L-box and U- box test. These tests are carried out to ensure that the mixes satisfy the requirement of SCC and to determine the effect of internal sulfate on the filling ability, passing and segregation resistance of SCC. The mechanical properties studied are the compressive strength, splitting strength, flexural strength, and modulus of elasticity. These tests are to be investigated under the effect of salt attack . Furthermore, a non– destructive test method is used, which is ultrasonic pulse velocity used to assess the dynamic properties of concrete. At age 28 days, compressive strength for all mixes ranges between (23.81-44.09) MPa for standard cubes measuring 150 mm and (16.56- 25.95) MPa for cylinders 150x300 mm, the compressive strength at 60 days, ranges between ( 23.51-36.57) and ( 13.24-30.87) MPa for cubes and cylinder respectively. It appears from the results that the compressive strength of mixes with external salts is larger than the mixes with internal sulphates for ages 28,60 and 90 respectively except that at age 180 days the mix L5 is the highest.