Influence of aggregate characteristics on the plant growing environment of the planting concrete with SAC

• Published in: Journal of cleaner production Vol. 445; p. 141179
• Main Authors: Jin, Shanshan, Zhang, Yang, Yan, Yuling, Xu, Zengmiao, Li, Aodong, Wang, Juan, Liu, Pengfei, Li, Liuhuan, Wang, Zhihua
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.03.2024
• Subjects: Plant growing environment; Planting concrete; Recycled concrete aggregate; Recycled red brick aggregate; Water retention ability; Plant growing environment; Planting concrete; Recycled red brick aggregate; Water retention ability; Recycled concrete aggregate
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2024.141179

To further utilize aggregates recycled from solid waste as the replacement of natural aggregate in the planting concrete, natural aggregate, recycled red brick aggregate and recycled concrete aggregate were selected to analyze the influence of the aggregate characteristics on the plant growing environment of the planting concrete with SAC (Sulphoaluminate Cement). Firstly, the chemical characteristics, micro morphology and pore structure of aggregates were evaluated by XRF, SEM and MIP, respectively. The geometry characteristics of the connecting voids in the planting concrete were quantified based on CT data. Additionally, a mathematical model of water absorption and reversion was proposed. Finally, the plant growing environment of planting concrete with different aggregates was compared and the mechanisms were explained. The results suggested that the planting concrete with different types of aggregate reach similar pH value at 28d but differs in the geometry characteristics of the connecting voids. The porosity of aggregates influences the mechanical properties of the planting concrete and its water absorption and reversion ability. A higher porosity of pores above 100 nm in the aggregates results in greater initial water absorption rates, a higher saturation water absorption rates, and a stronger continuous water reversion ability. A higher porosity of pores below 100 nm in aggregates results in stronger continuous water absorption ability and higher residual water content.