Amgad A. Hussein

PROPERTIES OF HIGH-STRENGTH CONCRETE AT LOW TEMPERATURES

This investigation deals with the effect of cold ocean water on the mechanical properties of green high strength concrete containing silica fume and fly ash. Tests were performed on cylinders exposed for periods of over 3 months, in cold ocean water, to temperatures varying from -10 to 20 C. The test specimens were exposed after 24 hr of normal curing. Preliminary results of the investigation indicated that low temperature affects both strength and elasticity of concrete. For the specimens exposed to cold ocean water, the gain in strength at 28 and 91 days was 40 and 54 % of the 3-day strength at room temperature. However, for the specimens exposed to temperatures of -10 C, the strength at 28 and 91 days was 97 and 91 % of the 3-day strength at room temperature, respectively. This low rate of maturity may be attributed to the fact low temperature slows down the main hydration process. Thus the rate of evolution of calcium hydroxide will be decreased, and the secondary pozzolanic reaction will be ceased.

Probabilistic and Statistical Modeling of Chloride-Induced Corrosion for Concrete Containing Metakaolin

AbstractThis paper presents new models for computing the chloride-induced corrosion period based on combining Monte Carlo simulation and statistical analysis methods. The study is divided into two ...