化学改性钢渣粉的安定性及其浆体的性能研究

Study on the Stability of Chemically Modified Steel Slag Powder and Its Slurry Properties

为了提高钢渣粉的安定性和力学性能,对原钢渣进行了改性试验。通过X射线衍射、傅里叶变换红外光谱、水化量热等表征方法,研究了改性前后钢渣粉矿物组成的变化及改性后钢渣粉复合水泥的水化活性、强度发展和安定性。结果表明,部分CaCO_(3)、Ca(OH)_(2)和钙铁矿与H_(2)SO_(4)反应生成CaSO_(4)。碱活化钢渣的水化放热和钙硅比较低,Ca(OH)_(2)结晶减少,影响了强度的发展。水蒸气加速了f-CaO的水化反应,显著提高复合浆体的后期强度。改性后的钢渣粉促进了原钢渣浆体和活性矿物的水化反应。钢渣浆体经过弱酸、弱碱、强酸、强碱、矿粉和水蒸气改性后,其48 h水化热较原始钢渣浆体分别提升2.50%、-72.62%、81.67%、42.99%和110.63%,醇胺能促进钙矾石(AFt)和单硫型水化硫铝酸钙(AFm)形成,促使结构致密化,但助磨剂改性对浆体的稳定性影响有限。

In order to improve the stability and mechanical properties of steel slag powder,the modification test of raw steel slag was carried out.The changes in mineral composition of steel slag powder before and after modification,as well as the hydration activity,strength development and stability of modified steel slag powder composite cement were studied by characterization methods such as X-ray,Fourier transform infrared spectroscopy and hydration calorimetry.The results showed that some CaCO_(3),Ca(OH)_(2) and calcium ferrite reacted with H_(2)SO_(4) to form CaSO_(4).The exothermic hydration and calcium-silica ratio of alkali-activated steel slag were low,and the crystallization of Ca(OH)_(2) was reduced,which affected the strength development.Water vapor accelerated the hydration reaction of f-CaO,which significantly improved the late strength of the composite slurry.The modified steel slag powder promoted the hydration reaction of the original steel slag slurry and the active minerals.The 48 h heat of hydration of the steel slag slurry modified with weak acid,weak base,strong acid,strong base,mineral powder and water vapor was enhanced by 2.50%,-72.62%,81.67%,42.99%and 110.63%,respectively,as compared to that of the original steel slag.The alcoholic amine promoted the formation of AFt and AFm and induced the structure to be densified,but the mill aid modification had limited stabilization improvement of the slurry.