Several Key Techniques About Construction Material Resourcialization Of Sea Sand

Exploitation the resources of ocean in reason is necessity when people face the questions of resources urgent, energy crisis and deteriorate environment. Aggregate is scarcity as the development of economic construction. On the other hand, sea sand is enrich. It can saving and protection eco-environmental if using sea sand as aggregate. Since sea sand has some deleterious salt, it is important for the research of the early hydration of concrete and solidified of chloride by cement matrixs.This article is based on elimination the deleterious salt of sea sand. Fist it makes a systematic study of the component, the construction, effects of mineral admixtures. Then, it explicates their effects on the concrete early hydration, microstructure, physical and mechanical character to concrete, particularly discuss the mechanism of mineral admixtures solidify to chloride. The main achievements of this article include:1) Using a new non-contact resistivity meter, hydration heat apparatus with multi-channel, test the paste with different water-binder ratio and composition of mortar. Experiment shows: cure of resistivity can well characterization the progress of paste hydration. Sea sand not only enhance paste early bending strength , compressive strength, elevation hydration heat, but also make the turning point of the resistivity cure ahead of time.2) Using chloride ion-selective electrode to test different constituents of composites effect to unit binding of Cl~-. Under the conditions of this experiment the cement concrete components' and mineral admixtures' unit binding of Cl" are as follow: cement (0.96 mg/g)> fly ash (0.85 mg/g)> silica fume (0.46 mg/g)> slag (0.21 mg/g); With the development of hydration, the content of solubility Cl~ will lower. Because the ability of physical sorption and chemical binder will elevation; With the increasing of W/C and decreasing of cement-aggregate ratio, the content of solubility Cl~- will increasing. Large porosity and fewer C-S-H gel will decline the binder ability of Cl~-. Hydrate's capability of bind Cl~- is Calcium Aluminates Hydrates and C-S-H gel. Calcium Aluminates Hydrates binding the Cl~- as "Friedel", C-S-H gel has well capability of binding Cl~ is by the great specific surface & double layer. It's can be approved by the SEM.3) It's better to using 25% FA or 50% Slag replacing cement when using sea sand asmaterial of foundation treatment, road building and dike construction t.Based on the result of this experiment we further study the feasibility of solidified of deleterious salt by cement matrixs, provides theoretical testimonies and technical support for the use of sea sand.