Zafar Tayyab, Zafar Muhammad Saeed, Hojati Maryam
Gerald May Department of Civil, Construction, & Environmental Engineering, University of New Mexico, Albuquerque, NM 87131, USA.
Materials (Basel). 2025 Jul 15;18(14):3327. doi: 10.3390/ma18143327.
This study investigates the feasibility of pumice-based internal curing based on the 3D printability of engineered cementitious composites (ECCs) for water-scarce environments and arid regions. Natural river sand was partially replaced with the presoaked pumice lightweight aggregates (LWAs) at two different levels, 30% and 60% by volume, and 50% of the cement was replaced with slag to enhance sustainability. Furthermore, 2% polyethylene (PE) fibers were used to improve the mechanical characteristics and 1% methylcellulose (MC) was used to increase the rheological stability. Pumice aggregates, presoaked for 24 h, were used as an internal curing agent to assess their effect on the printability. Three ECC mixes, CT-PE2-6-10 (control), P30-PE2-6-10 (30% pumice), and P60-PE2-6-10 (60% pumice), were printed using a 3D gantry printing system. A flow table and rheometer were used to evaluate the flowability and rheological properties. Extrudability was measured in terms of dimensional consistency and the coefficient of variation (CV%) to evaluate printability, whereas buildability was determined in terms of the maximum number of layers stacked before failure. All of the mixes met the extrudability criterion (CV < 5%), with P30-PE2-6-10 demonstrating superior printing quality and buildability, having 16 layers, which was comparable with the control mix that had 18 layers.
本研究基于工程水泥基复合材料（ECCs）在缺水环境和干旱地区的3D打印适用性，探讨了基于浮石的内部养护的可行性。用预浸泡的浮石轻集料（LWAs）按体积比30%和60%两个不同水平部分替代天然河砂，并用矿渣替代50%的水泥以提高可持续性。此外，使用2%的聚乙烯（PE）纤维改善力学性能，使用1%的甲基纤维素（MC）提高流变稳定性。将预浸泡24小时的浮石集料用作内部养护剂，以评估其对打印适用性的影响。使用3D龙门式打印系统打印了三种ECC混合料，CT-PE2-6-10（对照）、P30-PE2-6-10（30%浮石）和P60-PE2-6-10（60%浮石）。使用流动台和流变仪评估流动性和流变性能。通过尺寸一致性和变异系数（CV%）测量挤出性以评估打印适用性，而通过破坏前堆叠的最大层数确定可建造性。所有混合料均符合挤出性标准（CV<5%），P30-PE2-6-10表现出优异的打印质量和可建造性，有16层，与有18层的对照混合料相当。
