Huang Chih-Ming, Wang Her-Yung, Yang Wein-Duo, Kao Tien-Chun, Fang Sing-Yuan
Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 807, Taiwan.
Department of Civil Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 807, Taiwan.
Materials (Basel). 2022 Aug 2;15(15):5305. doi: 10.3390/ma15155305.
Cement mortar can be colored using color additive technology to give colorful facades to the surfaces of buildings, and to beautify the environment. In this study, weight ratios of color powder/cement at 1:80, 1:40, and 1:27, and polyacrylic emulsion/cement at a ratio of 1:5 were added as pigments to cement mortar; the fresh properties, slump, slump flow, hardened properties, compressive strength, flexural strength, ultrasonic pulse velocity, durability, surface electrical resistivity and thermal conductivity of the colored cement mortar were then examined. The results showed that adding color powder/cement at 1:80 and polyacrylic emulsion/cement at 1:5 gives the best water/cement (W/C) ratio, which equals 0.5; this can effectively improve the hardness and durability of colored cement mortar. At 28 days of aging, the strength of the various colored cement mortars was maintained at 33.1-36.8 MPa. The acrylic-based emulsion significantly improved the flexural strength of the specimen. At 91 days of aging, all of the cement mortars exceeded the control group, with an anti-bay strength of 19.9-21.7 MPa, and the strength increased with aging. Adding appropriate amounts of inorganic color powder and mixing water can effectively enhance the fresh and hardened properties and durability of the colored cement mortar, while polyacrylic emulsion may significantly improve the test pieces and flexural strength, which increases with age. Moreover, natural α-FeO (rust layer) is formed on the surface of the colored cement mortar samples through the addition of inorganic color powder that contains Fe(III) ion; this prevents the intrusion of noxious ions and thus increases the durability. All of the test pieces of colored cement mortar in this study had a surface resistance of over 20 kΩ-cm on the seventh day of the test period, meaning good surface compactness. In addition, because the thermal conductivity of the added inorganic color powder was higher than that of cement, the thermal conductivity was significantly improved.
水泥砂浆可采用彩色添加剂技术进行着色，使建筑物表面呈现出色彩斑斓的外观，美化环境。在本研究中，分别以1:80、1:40和1:27的色粉/水泥重量比，以及1:5的聚丙烯酸乳液/水泥重量比作为颜料添加到水泥砂浆中；然后检测了彩色水泥砂浆的新拌性能、坍落度、坍落扩展度、硬化性能、抗压强度、抗折强度、超声脉冲速度、耐久性、表面电阻率和导热系数。结果表明，添加1:80的色粉/水泥和1:5的聚丙烯酸乳液/水泥可得到最佳水灰比（W/C），其值为0.5；这可有效提高彩色水泥砂浆的硬度和耐久性。在养护28天时，各种彩色水泥砂浆的强度保持在33.1 - 36.8MPa。丙烯酸基乳液显著提高了试件的抗折强度。在养护91天时，所有水泥砂浆均超过对照组，抗折强度为19.9 - 21.7MPa，且强度随养护时间增加。添加适量无机色粉和拌合水可有效提高彩色水泥砂浆的新拌及硬化性能和耐久性，而聚丙烯酸乳液可显著改善试件和抗折强度，且强度随龄期增加。此外，通过添加含Fe(III)离子的无机色粉，在彩色水泥砂浆样品表面形成天然α-FeO（锈层）；这可防止有害离子侵入，从而提高耐久性。本研究中所有彩色水泥砂浆试件在试验期第7天的表面电阻均超过20kΩ·cm，表明表面密实性良好。此外，由于添加的无机色粉的导热系数高于水泥，导热系数得到显著提高。
