The CO₂ emissions from the cement industry and the production of waste wood chips are increasing with the rapid growth of the construction industry. In order to develop a green environmental protection building material with low thermal conductivity and up to standard mechanical properties, in this study, pine waste wood chips were mixed into cement-based materials as fine aggregate, and three different kinds of cementitious binders were used, including sulfur aluminate cement (SAC), ordinary Portland cement (OPC), and granulated blast furnace slag (GBFS), to prepare a recycled light cementitious composite material. The mechanical, thermal conductivity, shrinkage, water absorption, and pore structure of a wood chip light cementitious composite material were studied by changing the Ch/B (the mass ratio of wood chip to binder). The results showed that the strength, dry density, and thermal conductivity of the specimens decreased significantly with the increase in the Ch/B, while the shrinkage, water absorption, and pore size increased with the increase in the Ch/B. By comparing three different kinds of cementitious binders, the dry density of the material prepared with OPC was 942 kg/m³, the compressive strength of the material prepared with SAC was 13.5 MPa, and the thermal conductivity of the material prepared with slag was the lowest at 0.15 W/m/K. From the perspective of low-cost and low-carbon emissions, it was determined that the best way to prepare a light cementitious composite with waste wood chips is to use granulated blast furnace slag (GBFS) as the cementitious binder.

In this paper, the properties of sulphoaluminate based recycled concrete, with high workability and low and medium strength, prepared by recycled powder (RP), recycled coarse aggregate (RCA), and high belite sulphoaluminate cement (HBSAC), were systematically studied. Under the condition of a water binder ratio of 0.45, sulphoaluminate based recycled concrete, with different mix proportions, was prepared by replacing sulphoaluminate cement with RP and natural coarse aggregate (NCA) with RCA. The workability, mechanical properties, durability, and hydration products of the prepared concrete were analyzed. The results showed that when RP and RCA were used together, the workability of recycled concrete could fully meet the pumping demand in actual construction. When the mass replacement rate of RP was less than 30% and that of RCA was less than 20%, the strength of recycled concrete could completely reach the design strength grade, while those that did not reach the design strength grade could reach the next grade. The durability performance was also good.