Simulation of Water Pressure on Washout of Underwater Concrete Repair

ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

  


Title: Simulation of Water Pressure on Washout of Underwater Concrete Repair

Author(s): Joseph J. Assaad, Yehia Daou, and Kamal H. Khayat

Publication: Materials Journal

Volume: 106

Issue: 6

Appears on pages(s): 529-536

Keywords: hydrostatic pressure; interfacial velocity; underwater concrete; washout loss

Date: 11/1/2009

Abstract:
A comprehensive research project was undertaken to evaluate the effect of hydrostatic pressure and interfacial concrete/water velocity on the performance of underwater concrete (UWC) designated for repair applications. Washout loss was determined on 33 optimized mixtures using the CRD C61 test method, as well as a newly developed device enabling the simulation of concrete washout placed at various depths down to 140 m (460 ft) below water surface level. Test results showed that washout loss of UWC increases with the increase in water head. Depending on the mixture composition, a critical threshold water depth can be found, beyond which significant washout loss could take place. The effect of decreasing the interfacial concrete/water velocity from 2.5 to 0.5 m/s (8.2 to 1.6 ft/s) was found to reduce washout loss for a given depth of casting or enable the casting in deeper water for a given washout resistance. Good correlations were obtained between washout loss determined as per the CRD C61 test method and the washout loss derived from estimates given a certain interfacial concrete/water velocity and water depth.