矿渣掺量对高水胶比水泥净浆水化产物及孔结构的影响

EFFECTS OF SLAG DOSAGE ON HYDRATION PRODUCTS AND PORE STRUCTURE OF CEMENT PASTE AT HIGH WATER TO BINDER RATIO

测定了水胶比为0.5、矿渣质量分数为30%～80%的硬化水泥浆体中Ca(OH)2和非蒸发水量、孔径分布及孔隙率,以确定矿渣在高水胶比条件下的合理掺量.结果表明:即使在矿渣为大掺量情况下也能够改善浆体孔结构,而非蒸发水量、孔隙率随矿渣掺量的变化而变化,并存在使水化产物含量最多、浆体孔隙率最低的矿渣最佳掺量.在矿渣为大掺量情况下,Ca(OH)2含量可降低到极低.在比较纯水泥浆体和掺矿渣浆体的非蒸发水量和孔隙率的基础上提出了矿渣最大有益掺量,矿渣的掺量低于此值时,可使材料的性能得到改善.

To determine the reasonable dosage of slag in cement paste at high water to binder ratio, content of non-evaporable water and calcium hydroxide, porosity and pore size distribution of pastes with 30%-80% slag replacement for cement at a fixed water to binder ratio of 0.5 were tested. Results show that pore structure can be improved by adding slag even at high incorporating proportion. The non-evaporable water content and porosity vary with the dosage of slag, and there is an dosage for slag, in which the porosity of paste reaches to the lowest level and the content of non-evaporable water reaches to the highest, while the calcium hydroxide content can be reduced to a very low level at the high slag dosage. By comparing non-evaporable water content and porosity of pastes with and without slag, the maximum dosage beneficial to properties of slag is suggested. Under the maximum dosage the properties of cement-based materials can be improved.