磷石膏基自流平建筑腻子的实验研究

Experimental Investigation on Gypsum-Based Self-Leveling Building Putty Materials

本文通过对磷石膏改性煅烧制得β型半水石膏,以β石膏母体并掺入适当比例的矿渣、粉煤灰、生石灰及若干改性剂,成功研制出具有自流平性能的新型磷石膏基建筑腻子。利用XRD、SEM和EDS等微观手段,分析了自流平材料的微观结构。结果表明,在本反应体系中,β型半水石膏可与矿渣、生石灰等发生水化反应,从而形成较多的钙矾石针状晶体,能有效提高产物的工作性能和力学性能。其中,样品的7d和28 d抗压强度分别达到21.2 MPa和35.9 MPa,初凝时间和终凝时间分别为124 min和140 min。在苯乙烯–丙烯酸共聚物的作用下,粘结强度可达0.48 MPa,满足自流平墙体腻子的使用标准。

The phosphogypsum was calcined to obtain β-hemihydrates gypsum. The obtained β-hemihydrates gypsum was mixed with slag, fly ash, quick lime and modifiers. After hydration, the self-leveling construction putty based on gypsum was prepared. The microstructures of the materials were characterized by XRD, SEM and EDX. The results indicate that many ettringite acicular crystals were formed after hydration. The product after 7-day and 28-day hydration exhibited compressive strength of 21.2 MPa and 35.9 MPa, while the initial and final setting times were 124 min and 140 min, respectively. With the addition of styrene acrylic copolymer, the bonding strength can reach 0.48 MPa, which meets the standard of self-leveling wall putty.