Smart structures have attracted significant research attention in the last decade, mainly due to the capabilities of advanced concrete in electrical resistance-enabled self-sensing. In this study, we present a type of environment-friendly, self-sensing concrete enabled by electrical resistance. Environment-friendly, self-sensing concrete was casted with the additions of byproduct wastes (i.e., coal fly ash (FA), blast furnace slag (BOF) and red mud (RM)) at various volume fractions and cured using the conditions of 3, 7 and 28 days. The self-sensing concrete samples were experimentally tested to investigate the effects of the byproduct wastes on the mechanical and electrical properties (i.e., compressive strength and electrical resistance). In the end, parametric studies were experimentally conducted to investigate the influences of the byproduct wastes on the mechanical and electrical properties of the reported environment-friendly, self-sensing concrete.

With the continuous expansion of the global automobile fleet, there is an escalating demand to enhance and maintain current road infrastructure. Given the information provided, there will be a growing demand for bitumen, a key raw material used in the manufacturing of asphalt. Bitumen may account for up to 60% of the total usage in asphalt production. This study aims to determine the effect of different content of polylactic acid (PLA) on the change in the chemical and physical properties of biopolymer bitumen during its modification. This study was carried out by using a sample of petroleum road bitumen from CASPI BITUM (Kazakhstan) and a sample of PLA from Zhejiang Hisun (China). As a part of the research, the change of quality indicators of biopolymer bitumen when adding 4%–10% of PLA to it has been established. The results showed that the values of the average molecular weight and average molar mass increased with increasing the content of PLA in biopolymer bitumen. In particular, when the PLA content in biopolymer bitumen increased up to 10%, the average molecular weight of the biopolymer bitumen increased from 1,263 to 2,759 Mw and the average molar mass increased from 1,215 to 1,395 Mn. It was shown that increasing the PLA content in biopolymer bitumen from 0% to 10% leads to an increase in the softening temperature from 47 to 70°C or ∼ 49%. It was found that all examined samples of biopolymer bitumen are characterized by increased plasticity at 25°C (>100 cm). It has been established that the addition of 8% PLA to bitumen allows one to obtain a biopolymer bitumen of optimal quality. The results obtained can be used to produce road biopolymer bitumen.

This paper evaluates the geopolymer concrete produced using industrial waste and waste glass obtained by crushing glass materials. Geopolymer concrete mixtures were prepared with a water-to-binder ratio of 0.35 and an alkali activator solution to binder ratio (AAS/B) of 0.5 and 0.4. The partial substitution of sand by waste glass was 10%, 20% and 30%. Laboratory results showed that the compressive strength of geopolymer concrete increased with the addition of waste glass for a geopolymer concrete with AAS/B = 0.5, but decreased for AAS/B = 0.4. The expansion due to the alkali-silica reaction (ASR) was below 0.1% which is the expansion limit. The shrinkage of geopolymer concrete during drying decreases with an increase in glass content. The results of this study indicate that using glass as a partial sand substitute in geopolymer concrete provides sufficient mechanical properties. In addition, the production of this concrete will improve environmental conditions by reducing the extraction of raw materials and recycling waste glass.

The introduction of innovative 3D printing technologies in the construction industry makes it possible to increase the efficiency and environmental sustainability of materials. In parallel with the development of this technology, there was a need to create modification mixtures using waste materials. This study examines the use of waste-based modification additives in construction 3D printing technology. The main physico-mechanical properties and strength of fine-grained concretes formed by the method of layered extrusion show the high efficiency of using a modification mixture in the production of cements, mortars and concretes with a given complex of rheotechnological properties, depending on the composition of raw materials mixtures, interaction conditions and conditions. In the course of the study, the properties of waste materials are studied and the possibility of their use in the composition of building mixtures used for 3D printing is analyzed. Various experiments were carried out in order to determine the efficiency of waste materials and their effect on the physical and mechanical properties of building materials. As a result, it was found that waste-based modification additives contribute to increasing the strength, stability and environmental friendliness of building materials in construction 3D printing technology. It aims to provide new opportunities and solutions in the construction sector, considering the environmental benefits and economic benefits of these approaches.