Barnat-Hunek Danuta, Góra Jacek, Widomski Marcin K
Faculty of Civil Engineering and Architecture, Lublin University of Technology, Nadbystrzycka 40, 20-618 Lublin, Poland.
Faculty of Environmental Engineering, Lublin University of Technology, Nadbystrzycka 40 B, 20-618 Lublin, Poland.
Materials (Basel). 2020 Dec 29;14(1):101. doi: 10.3390/ma14010101.
The aim of the research presented in this paper is to evaluate the feasibility of using hydrophobic agents based on organosilicon compounds for surface protection of lightweight concrete modified with waste polystyrene. The experimental part pertains to the physical and mechanical properties of polystyrene-modified lightweight concrete. The concrete samples were prepared with the following ingredients: CEM I 42.5 R cement, recycled polystyrene (0-2 mm), quartz sand (0-2 mm), coarse river aggregate (2-16 mm), and water. Silane and tetramethoxysilane were employed for surface hydrophobization. Concrete with 20% polystyrene exhibits high porosity (25.22%), which is related to an increase in absorptivity (14.75%) compared to the reference concrete. The hydrophobized concrete is characterized by the lowest surface free energy (SFE) value, which is 7 or 11 times lower than the value of reference concrete, depending on the agents. The test on the contact angle (CA) was performed before and after the frost-resistance test (F-T test). Lower SFE translates into lower adhesive properties, higher resistance of the material to the infiltration of water and corrosive compounds, e.g., salts, and higher resistance to freezing and thawing cycles. Silane and tetramethoxysilane coating raised frost resistance by 54-58% compared to the reference samples. This agent reduced absorptivity by 30%. Recycled polystyrene can be successfully used to produce lightweight concrete (LC) with high durability provided by hydrophobic/icephobic coatings.
本文所呈现的研究目的是评估使用基于有机硅化合物的疏水剂对用废弃聚苯乙烯改性的轻质混凝土进行表面防护的可行性。实验部分涉及聚苯乙烯改性轻质混凝土的物理和力学性能。混凝土样品由以下成分制备而成：CEM I 42.5 R水泥、再生聚苯乙烯（0 - 2毫米）、石英砂（0 - 2毫米）、粗河骨料（2 - 16毫米）和水。硅烷和四甲氧基硅烷用于表面疏水化处理。含20%聚苯乙烯的混凝土具有较高的孔隙率（25.22%），与参考混凝土相比，其吸收率有所增加（14.75%）。经疏水化处理的混凝土的特征在于其表面自由能（SFE）值最低，根据使用的试剂不同，该值比参考混凝土的值低7倍或11倍。在抗冻性试验（F - T试验）前后进行了接触角（CA）测试。较低的表面自由能转化为较低的粘附性能、材料对水和腐蚀性化合物（如盐）渗透的更高抗性以及对冻融循环的更高抗性。与参考样品相比，硅烷和四甲氧基硅烷涂层使抗冻性提高了54 - 58%。这种试剂使吸收率降低了30%。通过疏水/憎冰涂层，再生聚苯乙烯可成功用于生产具有高耐久性的轻质混凝土（LC）。
