Experimental study of factors affecting mechanical properties for biomimetic mineralized mortar with polyacrylic acid modifier

Abstract

The development of novel cementation materials has attracted extensive interest due to the limitation of traditional cementation materials on environment. This study proposed a biomimetic mineralized mortar (BMM) based on the biomimetic chemically induced calcium carbonate precipitation (BCICP) using polyacrylic acid (PAA) as a modifier. The unconfined compression test (UCS) and scanning electron microscopy (SEM) were conducted to verify the effectiveness in improving the mechanical properties of BCICP treated samples. Moreover, the effects of cement solution ratio, cement solution concentration, and cement solution amount were investigated and an optimal scheme for BMM were further studied. The results show that the cement solution ratio and concentration would affect the form, size, and agglomerating mode of the calcium carbonate, thereby affecting the mechanical improvement. With the increase of the cement solution amount, the cementing behavior of calcium carbonate changes, which can be mainly divided into the following stages: bridging connection, pore filling, and film coating. In addition, Pearson correlation coefficient indicates that the UCS has a general tendency to increase with the calcium carbonate content. Compared to previous researches, the biomimetic mineralized mortar with PAA modifier shows excellent mechanical performance. The UCS of the sample treated by PAA is significantly greater than that of the sample treated by L-Asp or boric acid modifier with the same calcium carbonate content.