# Effect of Inense Ash on the Engineering Properties of Cement-Based Composite Material
###### Abstract  
This study investigated the effect of substituting cement with incense ash on material properties and hydration of cement-based composite materials. Test specimens with incense ash replacing up to 30% (volume) of cement were produced and cured at 25 \({}^{\circ}\)C and 75 \({}^{\circ}\)C for up to 120 days. The researchers of this study observed the effect on setting time, heat conduction, compressive strength, and water absorption, and conducted a microanalysis to observe the structural change of hydration products. The results indicated that by substituting cement with incense ash, the hydration reaction was hastened, and the setting time shortened. When 5% of cement was replaced, incense ash had the effect of filling the voids between particles. At a higher curing temperature, the frequency of particle collisions increased, expedting the hydration reaction and improving the strength of the specimens. At a longer curing time, voids in the specimens were gradually filled by colloids, and pozzolanic reaction caused the amount of Ca(OH)\({}_{2}\) to diminish and C-S-H gel to increase, which in turn improved the structural cohesion, reduced the water absorption, and increased the strength and thermal conductivity of the specimens. n pacs: 11.40.Hc, 11.40.Hc, 11.  
reduced alkalinity in the ash and an increase in calcium oxide [8; 9]. Moreover, raising the burning temperature can reduce the amount of metal elements such as K, Na, and Zn [10]. [PERSON] et al. [11] investigated the physical properties of wood ash and reported a specific weight of 2.43 g/cm\({}^{3}\), water content of 1.81%, and pH of 10.48. These properties make wood ash a suitable additive for cement. They also reported that when wood ash was used to replace 20-30% of cement, a slump of 0 resulted. [PERSON] [12] investigated the effect of wood ash on the slump of concrete and found that the amount of water required to maintain favorable workability increased as wood ash replaced cement [13]. [PERSON] et.al. [14] utilizes the biomass energy ash made from food and wood waste. The research results indicate that the biomass energy ash made from rice, meat, and vegetables has 71% carbon content instead of 1-2 wt% in cement mortar, which can make mortar have better resistance to penetration. Using the ash of biomaterials as a substitute for cement can enhance the strength and durability of cement-based composite materials and reduce their permeability and cost, making it a major topic in research on building materials [15]. Researchers have started to explore the use of ash of biomaterials with different properties in cement-based composite materials. For \(\check{}\)t et al. [16] replaced the biomass ash of coal with the fly ash of burned wood, and test results for specimens cured for 28 days indicated that wood-based biomass ash could replace up to 30% of conventional Portland cement; the ash contained fewer hazardous elements and could be added into cement directly without processing. [PERSON] et al. [17] used biomass ash as a substitute for cement and tested its effect on compressive strength and found that it can substitute cement up to 15%, the influence on the strength of which is mainly due to the hydration and the reaction of calcium silicate. [PERSON] et al. [18] replaced a portion of cement with rice husk ash and noted that doing so improved the durability and long-term strength of the concrete. In [PERSON] et al. [19], using wood waste as a resource for biomass gasification to turn it into biochar, the test results found that if appropriate biochar is added to the cement mortar, the compressive strength and flexural strength equivalent to the control group can be obtained, but it is broken. The capacity will be slightly increased. The application of wood biochar will not have a great negative impact on the mechanical properties of cement-based materials. It can also store the biochar in the building in the most stable manner, improving sustainable resource utilization. [PERSON] et al.