Study on capillary water absorption properties of polypropylene fiber coal gangue ceramsite concrete under freeze-thaw damage

In order to probe the effects of freeze-thaw damage and polypropylene (PP) fibres on the capillary water absorption of coal gangue ceramsite concrete (CGCC), the freeze-thaw cycle test and capillary water absorption test were carried out to study the effect of PP fibres content on the unit cumulative water absorption and water absorption rate of CGCC under freeze-thaw damage, establishing a model of initial capillary water absorption rate of PP fibre coal gangue concrete considering freeze-thaw damage. The results showed that, when freeze-thaw cycles were constant, the larger the PP fibres content was, the larger was the unit cumulative water absorption of CGCC. As the freeze-thaw cycles increased, the initial capillary water absorption rate of both PP fibre CGCC and CGCC showed a power function growth trend. In this study, the initial capillary water absorption rate prediction model was obtained through regression analysis, and the test results were in good agreement with the model prediction results.