China has a limited share of water resources per capita and a severe water scarcity. It is one of the world's countries with the most limited water resources per capita. Water resource challenges in China also include a lack of understanding of water conservation and water conservation, as well as major waste, pollution, and over exploitation. In order to solve the problem of inconvenient accurate calculation of pipeline head loss with complex layout, research on computer-aided design (CAD) head loss calculation method based on Plant Design Management System (PDSM) three-dimensional model is proposed. Firstly, the pressure pipe model is taken as the research object, and the straight pipe and pipe components of the calculated pipeline are classified and summarized according to the identification code of the three-dimensional model component library; Secondly, the head loss calculation formula is compiled and the corresponding logic between the calculation formula parameters and the PDSM three-dimensional model is established; Finally, the head loss of the same type of straight pipe and pipe components is calculated respectively. This calculation approach overcomes the drawbacks of the standard penstock head loss calculation method, such as the vast number of calculations required, erroneous calculation outputs, and lack of automation. Compared with the traditional calculation technology, the calculation accuracy is improved by 20%. It can calculate the pipeline head loss and local head loss synchronously, which is more accurate and simpler than the traditional calculation method.

Aims: In this study, the mechanical characterization of no-fines concrete solutions is addressed experimentally, with the purpose of possibly increasing their strength by using silica fume and embedded fibers (steel and nylon fibers) as possible efficient reinforcement. Background: Due to competition between developed and advanced countries, the contemporary construction sector is currently experiencing a shortage of fundamental building materials. In this regard, no-fines concrete is becoming increasingly popular, and it has been proven in the literature that it can offer some advantages as an economic and lightweight solution compared to conventional concrete. However, experiments and investigations are still needed to investigate the potential mechanical advantages for its efficient use in buildings, given that the major limitation compared to normal concrete is represented by limited strength. Objective: The primary objective of the present study is to assess the mechanical strength of no-fines concrete samples in which steel fibers, nylon fibers, and partial cement replacement with silica fume are used. For this purpose, no-fines concrete specimens are produced with fixed mix proportions of 1:6 cement-aggregate (c-a) ratio, various coarse aggregate gradations ((20-10) mm and (10-5) mm), and fixed w/c ratio (0.42). Methods: The experiments are carried out on cubes, cylinders and prisms of concrete samples with various aggregate solutions. The nominal length of both types of fibers is fixed at 20 mm. Steel fibers with 1 mm in diameter and nylon fibers with 0.3 mm, 0.4 mm, 0.5 mm, or 0.6 mm diameters, respectively, are taken into account to explore their effects on compressive strength, split tensile strength, and flexural strength. Results: The presented experimental results showed various mechanical advantages, such as increased compressive, splitting tensile and flexural strength parameters, for most of the examined samples. Nylon fibers, in particular, proved to significantly increase compressive, splitting tensile, and flexural strength values, compared to normal concrete, with additional benefits compared to steel fibers (for the examined arrangements and configurations). Conclusion: Overall, the examined compositions and mixtures of silica fume-based no-fines concrete samples encourage further investigations for the optimization of these solutions. In this regard, in addition to mechanical capacities, further key parameters (such as weight, cost, impact on concrete microstructure, etc.) will be taken into account.