The Structural Lightweight Concrete For Thermal Energy Storage

Question: Discuss about the Structural Lightweight Concrete For Thermal Energy Storage. Answer: Compressive strengths of concrete The necessity to get the compressive strength of concrete is that one gets to know the characteristics of concrete and whether concrete has been properly done. The compressive strength of concrete varies depending on the type of structures for which the concrete is intended. The compressive strength of concrete varies. It varies from 15 MPa (2200 psi) to 30 MPa (4400 psi). These depend on a number of factors like quality of concrete material, the strength of cement, water-cement ration as well as quality control when producing concrete. The testing of the compressive strength of concrete gets done on cylinder or cube (Hsu, 2017). Mix design for structural lightweight concrete The building industry is going higher and higher making the span of concrete to be longer and longer. It paves way for the growth of lightweight structural concrete. Lightweight concrete is a concrete with 2,000 psi for 28 days, with less than 115 pounds per cubic foot of air dry unit. In lightweight concrete mix design, keeping workability at the same time minimizing unit water content and getting the availability of mix water for hydration is a challenge. This is because there are high absorption rates as well as rough texture prohibiting the determination specific gravity of lightweight combinations. The application of specific gravity factor solves the problem. This method uses total water requirement and the amount needed to fulfill aggregate absorption characteristics it is established with the use of trial mixes (Hwang and Hung, 2005). The volumetric method is another method employed particularly when dealing with same materials. The initial design gets derived with the use of known volumes of moisture-free aggregates. The amount of water get determined with use of trial mixes and then added to secure the needed slump. On get the desired design, batch weights are converted with use of previous unit weight obtained from separate aggregate sizes. Batch weights are then balanced in the field for any dampness contained in the totals at the point of clustering. Even though the trial blends require some feeling with respect to the blend architect, combined with data that can be given by the producer, a few general standards ought to be remembered. On separate consideration of fine and coarse aggregate, the entire weight of one cubic yard of aggregate ranges from 30 to 32 cubic feet (Clarke, 2014). Porous materials for thermal energy storage in buildings The only storage concept in building is the use of porous materials with the chemical and physical sorption properties of gases that are reversible. It is a long-term solution for thermal energy storage in building because of its long-term, seasonal and low-temperature storage. These materials are capable of holding up to an approximate of 140oC of temperatures. The use of micro and meso-porous materials is essential. These micro and meso-porous materials entails a bigger aspect of solids that fall under micro-porous (0-2 nm) and meso-porous (2-50 nm) where the permeability must have a particular effect on the properties of the material as well as use (Zhou, Zhao, and Tian, 2012). The zeolites materials, zeolite-like materials, carbon molecular sieves, pillared materials, clathrasils, as well as clathrates, meso-porous materials, organic and/or inorganic porous hybrid materials (Schth and Schmidt, 2002) among others are examples of porous materials produced that can be utilized for b uildings. These PCM with the capability to store passive heat gains as latent heat in a given temperature range reducing energy usage, enhancing thermal comfort by adjusting the fluctuations in temperature and reducing peak loads (Jiang et al., 2010). References Clarke, J.L., 2014. Structural lightweight aggregate concrete. CRC Press. Hsu, T.T., 2017. Unified theory of reinforced concrete. Routledge. Hwang, C.L. and Hung, M.F., 2005. Durability design and performance of self-consolidating lightweight concrete. Construction and building materials, 19(8), pp.619-626. Jiang, H.L., Tatsu, Y., Lu, Z.H. and Xu, Q., 2010. Non-, micro-, and mesoporous metal organic framework isomers: reversible transformation, fluorescence sensing, and large molecule separation. Journal of the American Chemical Society, 132(16), pp.5586-5587. Schth, F. and Schmidt, W., 2002. Microporous and mesoporous materials. Advanced Materials, 14(9), pp.629-638. https://www.journals.elsevier.com/microporous-and-mesoporous-materials Zhou, D., Zhao, C.Y. and Tian, Y., 2012. Review on thermal energy storage with phase change materials (PCMs) in building applications. Applied energy, 92, pp.593-605.