聚苯乙烯颗粒掺量对混凝土力学性能和保温性能的影响研究

Effect of polystyrene particle content onmechanical properties and thermal insulation properties of concrete

以聚苯乙烯颗粒(EPS)作为掺杂材料,通过不同的表面活性剂对其进行亲水改性,在此基础上将聚苯乙烯颗粒掺入到泡沫混凝土中,研究了亲水改性后的聚苯乙烯颗粒对混凝土力学性能和保温性能的影响。结果表明,未改性的聚苯乙烯属于憎水材料,接触角为112°,三乙醇胺改性后接触角降低至31°,具有优异的亲水性。泡沫混凝土具有多孔特征,孔径分布为20~230μm,凝固时间随聚苯乙烯颗粒掺杂量的增多不断降低,流动度先增大后降低,EPS-0.9%的凝固时间为90 min,流动度最高为17.9 mm。随着EPS颗粒掺杂量的增多,泡沫混凝土的抗压强度持续降低,抗折强度先降低后轻微升高,导热系数和干密度先降低后增大,抗碳化性能持续降低。在28 d龄期时,EPS-1.2%试样的抗压强度达到最低值5.2 MPa,碳化深度达到最大值2.13 mm;EPS-0.6%试样的抗折强度达到最大值0.57 MPa;EPS-0.9%试样的干密度和导热系数达到最低值,分别为357 kg/m^(3)和0.069 W/(m·K),保温性能最优。

Polystyrene particles(EPS)were used as the doping material,which were hydrophilic modified by different surfactants.On this basis,polystyrene particles were added to foam concrete,and the effects of hydrophilic modified polystyrene particles on the mechanical properties and thermal insulation performance of concrete were studied.The results showed that unmodified polystyrene belongs to hydrophobic materials with a contact angle of 112°.After modification with triethanolamine,the contact angle decreased to 31°,indicating excellent hydrophilicity.Foam concrete had porous characteristics,and the pore size distribution was 20-230μm.The setting time decreased with the increase of polystyrene particle doping,the fluidity first increased and then decreased,the solidification time of EPS-0.9%was 90 minutes,and the highest fluidity was 17.9 mm.With the increase of EPS particles,the compressive strength of foam concrete continued decreasing,the flexural strength first decreased and then slightly increased,the thermal conductivity and dry density first decreased and then increased,and the carbonation resistance continued decreasing.At 28 d of age,the compressive strength of the EPS-1.2%sample reached the minimum value of 5.2 MPa,and the carbonization depth reached the maximum value of 2.13 mm.The flexural strength of the EPS-0.6%sample reached a maximum value of 0.57 MPa.The dry density and thermal conductivity of the EPS-0.9%sample reached the lowest values,which were 357 kg/m 3 and 0.069 W/(m·K),respectively,indicating the best insulation performance.