Influence of Fluidity on Reliability of SCC Produced Using Local Saudi Materials

Abstract

The reluctance in utilizing the advantages of Self Compacting Concrete (SCC) in Saudi Arabia stems from two contributing factors: lack of research or published data pertaining to locally produced SCC, and a feeling of doubt and uncertainty in the minds of practicing engineers about the reliability of SCC in its hardened stage. The primary aim of this study is to explore the influence of fluidity on reliability of 28-day compressive strength of SCC. For this purpose, six self compacting concrete mixes were prepared with the same water-powder ratio and other ingredients but with different fluidities. The fluidity was varied by altering the dosage of viscosity modifying admixture (VMA) and superplasticizer in different SCC mixes. Filling ability, passing ability, and resistance to segregation were evaluated to make sure that prepared mixes satisfy the SCC basic criteria. From each SCC mix, 9 cubes were cast to obtain compressive strength of SCC in the hardened stage after 28 days of curing. The test results of these specimens were used to carry out a probabilistic analysis of 28-day cube strength. The probability of achieving specified design strength was obtained by studying basic statistics (e.g. by obtaining mean, standard deviation, coefficient of variation, etc.) and probability distribution of cube strength. A simple methodology is presented to ascertain the probability distribution of 28-day cube strength. The obtained probability distribution of cube strength was then used to find the probability of achieving designed compressive strength value. The study shows that SCC prepared using local Saudi materials is equally reliable to conventional concrete provided it satisfies all the basic requirements of SCC in the fresh stage and maintains a minimum slump flow of 600 mm.