Light-transmitting concrete using ash and slag, and glass waste

Introduction. The article discusses the potential for producing “green” light-transmitting concrete products in Vietnam using the available resources of ash and slag and glass waste, which will contribute to the development of a closed-cycle economy and sustainable “green” transformation of industrial production in order to achieve zero carbon dioxide and other greenhouse gases emissions by 2050. The aim of the study is to develop formulations and manufacturing technologies for light-transmitting cement-free concrete products with sufficient strength using high-tonnage waste in the form of ash, slag, glass waste, etc. in combination with an activating solution. To achieve this goal, it was necessary to explore the possibility of using the multi-tonnage waste available in Vietnam, suitable for the production of light-transmitting concretes, in order to select the optimal raw materials, and to assess the potential volumes of suitable secondary resources. Materials and methods. The following raw materials were used in the study: finely ground blast furnace slag, fly ash from incineration power plants, glass waste, ceramic powder “TOTO”, obtained by crushing defective plumbing products, activating alkaline solution, polycarboxylate superplasticizer and water. The research methodology is based upon calculating the compositions of concrete mixtures for the production of light-transmitting cement-free concretes by the absolute volume method and testing the developed concretes to determine their average density, compressive and tensile strength during bending, water absorption and natural moisture of samples in accordance with current Vietnamese standards, as well as in assessing the light transmission capacity of the resulting concrete products. Results and discussion. As a result of the conducted research, compositions of decorative cement-free and light-conducting optical fiber-free concretes has been obtained using multi-tonnage man-made waste with sufficient strength (40÷50 MPa for compression and 11.5÷13 MPa for bending tension), low water absorption (6.5÷10% by weight) and good light transmission ability have been developed. Conclusion. A technology is proposed for the production of decorative thin panels and wall tiles in laboratory conditions that have the ability to transmit light and give architectural expressiveness to outside walls and interiors of residential and public buildings.