磷渣替代矿渣对水泥孔溶液pH值及水化进程的影响

Effect of Pore Solution pH Value and Hydration Process on Phosphorous Slag Replacing of Slag

针对不同掺量磷渣对矿渣水泥浆体水化行为的影响,测试了磷渣掺量0%-30%制备水泥浆体的各龄期强度,并对比了不同龄期浆体孔溶液的PH值,以及水化产物的差异。结果表明：磷渣可用作活性掺合料替代部分的矿粉,在考虑磷渣用量及保证浆体强度的同时,磷渣掺量不宜超过20%,此时浆体的7 d、28 d强度保证率分别在80%、90%以上,对应龄期抗压强度分别在30 MPa、50 MPa以上。而试件孔溶液p H值基本是随着磷渣替代矿渣量的增加呈现减小趋势。XRD图谱表明,随着磷渣替代矿渣掺量的增加,钙矾石晶体衍射峰强度变化有所减弱,说明磷渣掺量过多时,水化速率减慢。热重结果显示：同一龄期时,磷渣达30%时,C-S-H凝胶、钙矾石的形成有所减少;随着龄期的增长,水化产物逐渐增多,热重失重量依次增大。

Aimed at on hydration behavior of slag cement paste with different phosphorous slag content, influence of phosphorous slag dosage （0 - 30% ） on the cement paste intensity of various age of cement paste were tested in this paper; Furthermore, paste hole solution pH value at different ages and hydration products were systematically compared. Results show phosphorous slag can used as active admixture to replace part slag, phosphorous slag （ dosage within 20% ） with the compressive strength are more than 30 MPa and 50 MPa at 7 d and 28 d at 7 d separately, strength change rate of corresponding ages are 80% and 90% respectively. While, pore solution pH value of S1 - S4 present a decreasing trend with increasing of phosphorous slag . dosage . XRD analysis showed that, ettringite crystal diffraction peak is weakened with phosphorous slag dosage, these are shown that excessive phosphorus slag is not conducive to added hydrate slurry; it corresponds to a slower hydration. TG-DSC results showed that, the formation of CSH gel,ettringite are reducing with 30% phosphorous slag at the same age, while the hydration products gradually increased with increasing age, weight loss of TG-DSC is successively increased.