Micro-mechanism analysis of the influence of sawdust with different replacement ratio on concrete performances

Abstract

As a waste of wood processing, a large accumulation of sawdust will have an impact on the environment. In this paper, sawdust is added to concrete to explore the influence of sawdust on the performance of concrete. Experiments show that sawdust water absorption and friction are the key factors affecting the rheological properties. Through Inductively coupled plasma mass spectrometry, it can be understood that sawdust fiber can adsorb ions, so it will have an impact on early hydration. Nanoindentation shows that sawdust changes the properties of hydration products, which is related to the adsorption of ions by sawdust. Sawdust hurts the compressive strength and heat resistance of concrete. Mercury intrusion porosimetry and Ultrasonic pulse velocity results show that similar to wood chips will lead to a decline in the interfacial transition zone, resulting in increased porosity, but the adsorption of chloride ions on wood chips is beneficial to the protection of concrete, so in the appropriate dosage conditions, wood chips will not significantly affect the performance of concrete.