An investigation of the compatibility of different approaches to self-healing concrete: The superabsorbent polymers and microbially induced calcite precipitation

FIBRE CONCRETE 2019

土木建筑工程

Schreiberová, H.^1 ; Fládr, J.^1 ; Trtík, T.^1 ; Chylík, R.^1 ; Bílý, P.^1

Faculty of Civil Engineering, CTU in Prague, Thakurova 7/2077, Prague 6

166 29, Czech Republic^1

关键词: Calcite precipitation;    Durability of concrete structure;    Ionic composition;    Mechanical properties test;    Self-healing concretes;    Superabsorbent polymer;    Swelling capacities;    Water/cement ratio;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/596/1/012039/pdf
DOI  :  10.1088/1757-899X/596/1/012039

学科分类：土木及结构工程学

来源: IOP

【 摘 要 】

The concept of the self-healing concrete, thus an improvement of the durability of concrete structures, has become a widely investigated topic in recent decades. The aim of this study is to examine a possible combination of two existing approaches to the spontaneous crack-sealing - the biologically driven calcite precipitation and the addition of superabsorbent polymers (SAP) into the concrete matrix. Firstly, the paper compares the absorption rate of SAP in various solutions, including a nutrient-based solution which is used in the bio-concrete. The results show that the ionic composition of the liquid influence the swelling capacity greatly. In this study, the absorption rate of SAP in the nutrient-based solution is as low as 6% of the rate in distilled water. Thus, this finding could indicate a possible drawback of the combination of the proposed self-healing approaches. Further, this paper determines the impact of the SAP addition to cement paste with different water/cement ratios. In this experiment, the SAP is applied in various dosages (1% and 0.5% by c. w.) and states (a dry state or a fully swollen state). The conducted flowability and mechanical properties tests indicate a profound, generally negative, impact of the SAP addition on the cement paste characteristics. The paper then discusses possible adjustments of the SAP-cement paste composition and compares the present results with previous studies.