Construction of homogeneous structure and chemical bonding in bamboo scrap/magnesium oxychloride composites by polycarboxylate superplasticizer

This study was aimed to solve the problem of large waste from bamboo processing residues, improve the quality of building composites, give composites biological properties, and expand the use of composites. Highly efficient and excellent bamboo scrap/magnesium oxychloride composites were prepared, with homogeneous structure and chemical bonding constructed with magnesium oxychloride cementitious material as the raw material, bamboo scraps as reinforcement material, and polycarboxylate superplasticizer (PCE) as modifier. The influence of PCE addition on molding performance, mechanical performance, and water resistance of the resulting composites were examined and discussed. Scanning electron microscopy, X-ray diffractometry, and thermogravimetric analyses were used to characterize the microscopic morphology, crystal structure, and heat resistance of composites, respectively. The results showed that, when PCE addition was 0.3% (by vol), the fluidity of magnesium oxychloride slurries was conducive to composite molding, provided the best compressive strength, bending strength, and water resistance, and the composite performance observed to improve with extended storage time. In addition, with 0.3% PCE, the interface between bamboo scraps and the magnesium oxychloride matrix in the composite material was the best, showing more 5-phase crystals and the best heat resistance. This strategy not only improved the functionality of this kind of composite but also provided a good solution for the use of bamboo processing residues.