Recently, addition of various natural fibers to high strength concrete has aroused great interest in the field of building materials. This is because natural fibers are much cheaper and locally available, as compare to synthetic fibers. Keeping in view, this current research conducted mainly focuses on the static properties of hybridized (sisal/coir), sisal and coir fiber-reinforced concrete. Two types of natural fibers sisal and coir were used in the experiment with different lengths of 10, 20 and 30 mm and various natural fiber concentrations of 0.5%, 1.0%, and 1.5% by mass of cement, to investigate the static properties of sisal fiber reinforced concrete (SFRC), coir fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC). The results indicate that HFRC has increased the compressive strength up to 35.98% with the length of 20 mm and with 0.5% concentration, while the CFRC and SFRC with the length of 10 mm and with 1% concentration have increased the compressive strength up to 33.94% and 24.86%, respectively. On another hand, the split tensile strength was increased by HFRC with the length of 20 mm and with 1% concentration, CFRC with the length of 10 mm and with 1.5% concentration, and SFRC with the length of 30 mm and with 1% concentration have increased up to 25.48%, 24.56% and 11.80%, respectively, while the HFRC with the length of 20 mm and with 0.5% concentration has increased the compressive strength of concrete but has decreased the split tensile strength up to 2.28% compared to PC. Overall, using the HFRC with the length of 20 mm and with 1% concentration provide the maximum output in terms of split tensile strength.

This review article focused on the mechanical properties of sisal, coir and hemp fiber-reinforced concrete composites and several factors affecting the mechanical properties of natural fiber-reinforced concrete (NFRC) composites. Several treatments were applied to improve the surface of natural fiber for improving the strength and durability of composites. Recently researchers have investigated the mechanical properties by using NaOH treatments effects of sisal, coir and hemp fibers-reinforced concrete composite are highlighted in this study. A variety of recent studies showed that sodium hydroxide (NaOH) treatment plays a significant role in the adhesion of fiber concrete composites. It was found that NaOH improves the mechanical properties of the natural fiber-reinforced composites. Further, the treatment techniques for the modification of these natural fibers by improving the surface of these natural fibers are discussed. In the same way, previous research has investigated the effect of thermal stability and water absorption on the mechanical properties. Generally, this review article was aimed to highlight, gather, and explore the previous reported research studies leading the mechanical properties of sisal, coir and hemp fiber and its polymer composites to deliver a basis source of data and literature to expose it as composite materials like synthetic fibers.

Digital twin technology, a new type of digital technology emerging in recent years, realizes real-time simulation, prediction and optimization by digitally modeling the physical world, providing a new idea and method for the design, operation and management of water conservancy projects, which is of great significance for the realization of the transformation of water conservancy informatization to intelligent water conservancy. In view of this, this paper systematically discusses the concept and development history of digital twin smart water conservancy, compares its differences with traditional water conservancy models, and further proposes the digital twin smart water conservancy five-dimensional model. Based on the five-dimensional model of digital twin water conservancy, the research progress of digital twin smart water conservancy is summarized by focusing on six aspects, namely digital twin water conservancy data perception, data transmission, data analysis and processing, digital twin water conservancy model construction, digital twin water conservancy interaction and collaboration and digital twin water conservancy service application, and the challenges and problems of digital twin technology in the application of smart water conservancy. Finally, the development trend of digital twin technology and the direction of technological breakthroughs are envisioned, aiming to provide reference and guidance for the research on digital twin technology in the field of smart water conservancy and to promote the further development of the field.

Controlled Environmental Agriculture (CEA) has gained a lot of attention in recent years, mainly because of its ability to overcome extreme weather problems and ensure food safety. CEA can meet the full growth state monitoring of the crop period; however, the optimization of the growing environment is still limited by the algorithm defects. In this article, we present an optimization method of growing environment based on reinforcement learning, Q-learning and the time-series prediction model Informer. This approach is demonstrated for the first time as far as we know. By employing Informer, we predicted the growth of strawberries based on current environmental variables and plant status. The prediction results served as a reward to motivate Q-learning, guiding it to make optimal modifications to the environment in real-time. This approach aimed to achieve the optimal cultivation environment continuously. Two groups of validation experiments were conducted based on different cultivation objectives: “obtaining the most stolons” and “obtaining the highest fruit count”. Compared to the empirically planted groups, the experimental groups using the RL-Informer model achieved yield increases of 17.81% and 20.78%, respectively. These experiments highlight the outstanding performance of the proposed RL-Informer model in real-time prediction and modification of environmental variables.

The difference in force chains can be used to evaluate asphalt mixture skeleton structure. In this study, different asphalt mixture discrete element method models were established via the two-dimensional particle flow code software to analyze force chain identification criteria. And then, the force chain lengths of different asphalt mixtures were quantified preliminarily. Results indicate that the average contact force [ ] needs to be set as the contact force threshold value. The recommended angle threshold value is 45°. For asphalt mixtures, less than 50% aggregate content is involved in transferring external loading. Whether the aggregate is located on the force chains should be regarded as an important criterion to judge whether the aggregate is involved in the asphalt mixture skeleton composition. Although dense-graded asphalt concrete will generate many force chains, most of them are short length force chains that are not conducive to transferring load.