University of Khartoum

Expreimental Study on Selfcompacting Concrete

Expreimental Study on Selfcompacting Concrete

Show full item record

Title: Expreimental Study on Selfcompacting Concrete
Author: Osman, Murtada Khalid Abdelrahman
Abstract: This research aimed at the possibility of production of powder typeSelf Compacting Concrete (SCC) in Sudan with locally available aggregates. In addition, it explores effect of Dolomitequarrydust as replacement of cement and fly ash or sand with different replacement percents to improve the fresh and hardened properties of SCC. Furthermore, combinedNon-destructive tests methods (NDT) have been carried out to evaluate the in situ compressive strength beside the determination of Young’s modulus of Elasticity and Poisson’s ratio of SCC. Crushed coarse aggregates with max size of 20 mm was used, also natural coarse sand was used as fine aggregates. The total powder used was comprised of Type F fly ash and dolomitequarrydust. The quarry dust is a by-product of blasting and quarrying activities of dolomite/marble aggregate quarryfrom QARGADA Mountain at the Blue Nile State. The chemical analysis and X-ray diffraction of cement, fly ash and Dolo-Marble also had been studied. The main components of the quarry dust are calcium magnesium carbonate (dolomite) contaminated with amorphous silica (SiO2)and calcium sulphate (Gypsum material). Special equipment were used to measure the flowability, passing ability and segregation resistance of SCC mixtures. Hardened properties of SCC such as compressive strength, flexural strength, and Spilt tensile strength were investigated. The Poisson's ratio and E-modulus of SCC were also measured using longitudinal resonant frequency and Ultrasonic Pulse Velocity (UPV) methods. After different trialsa suitable mix for SCC, which satisfied the standards requirements, had been achieved successfully.The major difficulty in the development of SCC was the cement mortar should have higher viscosity to ensure flowability stability of mix. The fully replacement of Fly Ash with Stone Dustwas achieved with same hardened properties. It was also found that the use of15% of fly ash and 10% of Dolo-Marble dust of the total powder had the highest compressive strength. When the Dolomitedust used as partial replacement of sandbypercents up to 18% of the total sand(fine-coarse aggregate ratios less than 0.82),thefresh and hardened properties were positively affected.The Stone Dusts exhibited an excellent performance due to efficient micro-filling ability and pozzolanic activity when it was used as replacement material. Strong correlations with high confidence levels had been developed between some hardened properties and NDT results.
Description: 209 page
URI: http://khartoumspace.uofk.edu/123456789/16815
Date: 2015-10-29


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account