The use of synthetic fiber and natural fiber for concrete production has been continuously investigated. Most of the materials have become popular for their higher flexibility, durability, and strength. However, the current study explores the engineering properties of cement concrete reinforced with nylon and jute fibers together. Varying proportions and lengths of nylon and jute fibers were utilized in the concrete mixture. Hence, the combined effects of nylon and jute fibers on workability, density, water absorption, compressive, tensile, flexural strength, and drying shrinkage of concrete were investigated. Results showed that concrete with 1% of nylon and jute fibers together by the volume fraction showed a maximum enhancement of the compressive strength, split tensile strength, and flexural strength by 11.71%, 14.10%, and 11.04%, respectively, compared to the control mix of concrete at 90 days. However, the water absorption of concrete increased with increasing nylon and jute fiber contents. The drying shrinkage of concrete decreased with the addition of nylon and jute fibers together after 90 days. Thus, the sparing application of both nylon and jute fiber as discussed in this study can be adopted for concrete production.

Cementitious and recycled materials that have the potential to improve various properties of concrete have attracted the attention of many researchers recently. Different types of cementitious and recycled materials seem to possess certain unique properties to change cement concrete. This experimental study aims to investigate the impact of ground granulated blast furnace slag (GGBFS) and corn cob ash (CCA) as a partial replacement material for Portland cement (PC) and fine aggregate (FA), respectively, on fresh and hardened concrete properties, as well as the embodied carbon of concrete. The concrete mix was blended with 5–20% of GGBFS and 10–40% of corn cob ash, both individually and combined. A total of 300 concrete specimens were made to achieve the targeted strength of 25 MPa at a 0.50 water/cement ratio and cured at 28 days. It is observed that the workability of fresh concrete is lowered as the dosages of GGBFS and CCA increase in the mixture. Moreover, the compressive and split tensile strengths are augmented by 10.94% and 9.15%, respectively, at 10% of GGBFS by the weight of PC at 28 days. Similarly, the compressive and split tensile strengths are augmented by 11.62% and 10.56%, respectively, at 30% of CCA by the weight of FA at 28 days. Moreover, the combined use of 10% of GGBFS as a cementitious ingredient along with 30% of fine aggregate replaced with CCA in concrete provides the highest compressive and splitting tensile strength, with 16.98% and 13.38% at 28 days, respectively. Furthermore, the density and water absorption of concrete were reduced with increasing dosages of GGBFS and FA in concrete at 28 days. In addition, the embodied carbon and energy were also reduced as the replacement content of GGBFS along with CCA increased in concrete. It is concluded that 10% of GGBFS and 30% of CCA are the optimum percentages for structural applications to reduce the use of cement as well as the cost of the project.

Piezoelectric ceramics have good electromechanical coupling characteristics and a high sensitivity to load. One typical engineering application of piezoelectric ceramic is its use as a signal source for Weigh-In-Motion (WIM) systems in road traffic monitoring. However, piezoelectric ceramics are also sensitive to temperature, which affects their measurement accuracy. In this study, a new piezoelectric ceramic WIM sensor was developed. The output signals of sensors under different loads and temperatures were obtained. The results were corrected using polynomial regression and a Genetic Algorithm Back Propagation (GA-BP) neural network algorithm, respectively. The results show that the GA-BP neural network algorithm had a better effect on sensor temperature compensation. Before and after GA-BP compensation, the maximum relative error decreased from about 30% to less than 4%. The sensitivity coefficient of the sensor reduced from 1.0192 × 10⁻²/°C to 1.896 × 10⁻⁴/°C. The results show that the GA-BP algorithm greatly reduced the influence of temperature on the piezoelectric ceramic sensor and improved its temperature stability and accuracy, which helped improve the efficiency of clean-energy harvesting and conversion.

With the advantages of high strength, light weight, high corrosion and fatigue resistance, and low relaxation, carbon-fiber-reinforced polymer (CFRP) is an excellent cable material for cable-stayed bridges. However, the relatively high unit price of CFRP compared to that of steel may hinder the large-scale application of CFRP stay cables. This paper presents the economic comparison between long-span cable-stayed bridges using CFRP cables and the corresponding steel cable-stayed bridges through life-cycle cost analysis (LCCA). Three CFRP cable-stayed bridges with a main span of 600 m, 1200 m, and 1800 m, respectively, along with their steel counterparts, were designed, and their life-cycle costs (LCCs) were calculated. The comparison of LCCs was not only between the CFRP and steel cable-stayed bridges with the same span, but also between the cable-stayed bridges with different spans. Furthermore, the different unit prices of CFRP cables and different replacement frequencies of steel cables were also investigated. The results show that the initial design and construction cost of the long-span CFRP cable-stayed bridge is higher than that of the corresponding steel cable-stayed bridge, although using CFRP cables can reduce the materials used, primarily due to the higher unit price of the CFRP cable. Despite the higher initial cost, the long-span CFRP cable-stayed bridge can still achieve lower LCC than the steel cable-stayed bridge, because it has significantly lower rehabilitation cost and user cost, as well as slightly lower vulnerability cost. Furthermore, with the increase in the main span and the decrease in the unit price of CFRP cables, the LCC advantage of the long-span CFRP cable-stayed bridge becomes more obvious.

Due to the fact that steel reinforcement is vulnerable to corrosion, FRP bars with light weight, high strength, and excellent durability have become a good substitute for ordinary steel bars. FRP bars have high tensile strength, but their compressive strength is relatively low and often neglected, so the application of FRP bars in compression members has been restricted. This paper proposes a new pultrusion‐winding‐pultrusion method to improve the compressive ability of FRP bars. A hoop FRP layer is winded on the outer surface of the pultruded FRP core, and a longitudinal pultruded layer and ribs are also added on the outermost surface. In this paper, mechanical properties of this novel FRP bar with hoop winding layer are investigated. First, monotonic tensile and compressive tests on traditional and novel GFRP bars were conducted. Then, cyclic tension‐compression loading tests were also carried out on the two types of GFRP bars. Test results showed that the compressive ultimate bearing capacities of GFRP bars with winding layers were 10∼20 kN greater than those of the traditional GFRP bars, and the compressive ductility of the novel GFRP bars was also improved. Furthermore, the tensile stress‐strain behaviors of both GFRP bars were linear‐elastic and the added winding layer did not greatly influence the tensile properties of the GFRP bars. Moreover, for the cyclic loading test, the compressive ultimate load of GFRP bars was 80%∼90% of that under monotonic compressive test, and the tensile ultimate load was 45%∼65% of that under monotonic tensile test. Compared with the GFRP bar without winding layer, the overall stiffness of the novel GFRP bar was greater than that of the traditional one and the ultimate load of the novel GFRP bar was also greater. In addition, seeing that the residual displacement of the novel GFRP bar was greater than that of the traditional GFRP bar, winding hoop fibers on the outer surface of the core is a useful way to improve the energy dissipation capacity of the GFRP bar.