土木工程(国外英文资料).docVIP

土木工程(国外英文资料) 1. The main factors influencing setting time of cement, cement mineral composition and mineral admixtures (additive), cement fineness, mixing water consumption, environment temperature and humidity, gypsum content The effect of the concrete mixing material on the performance of hardened concrete will be affected: the formation of water secretion channel, and the formation of the capillary channel after hardening. The surface forms a loose layer, a weak layer; The forming of a water sac or water membrane under the coarse aggregate and the steel bar causes the binding force of the aggregate and steel and cement to decrease. Concrete durability is reduced The ratio of yield strength to limit strength is compared to the ratio of strength to strength. This ratio is a small representation of the strength of the structure due to local overload. But this ratio is too low to say that the utilization is low enough, not enough to make the economy; If showed relatively large said the utilization rate of the steel is larger, but the ratio is too large, small strength reserve, increase the tendency of brittle fracture, safe enough, therefore, its better to keep the ratio between 0.6 to 0.75, to be both safe and economic. Main factors that affect the strength of wood: water content, temperature, load time, defects. Describe the effect of water reducer on concrete: keep water consumption constant and increase liquidity. Keep the slump constant, reduce water use and increase intensity; Keep the slump and strength unchanged and save the cement; Improve the anti-permeability of concrete and slow the water heat rate of the early cement hydration As the saying goes, wood is a wet, dry, dry, wet, two and three years. Please analyze the reason. The fungus can survive and reproduce in the wood and must have three conditions, namely, proper moisture, air and temperature. But the moisture content of lumber in 35% ~ 50%, the temperature at 25 ~ 30 ℃, when again there is a certai