The recycling bio-waste shells problem has grown more and more serious in recent years and many efforts have been made to solve this problem. One possible solution is to put these bio-shells into concrete and recycle them as building materials using the aggregate matrix concrete approach. To verify the engineering feasibility, the mechanical properties of bio-shells aggregated concrete were invested via gradient substitution rates at 10%, 30%, and 50% with a total of 78 groups of specimens in this paper. Our results show that the mechanical properties of the concrete were enhanced in maximum flexural strength and maximum compressive. Economic performance was also analyzed and found that the costs of frame-shear structure, frame structure, and tube-in-tube structure were reduced by 10.2%, 10%, and 10.3%. The carbon environmental assessment also shows superiority in the carbon reduction of a single specimen with various rates of the shell. In summary, compared with ordinary concrete materials, it is very possible to use waste bio-shells as a substitute for aggregates to develop the sustainable recycling development of concrete materials.

Non-metallic fiber concrete is an emerging composite material that capitalizes on the exceptional strength, toughness, and durability of non-metallic fibers to enhance the mechanical properties and longevity of concrete. This article examines and explores the pertinent literature on non-metallic fiber concrete, considering various types and dosages. It also analyzes the impact and mechanisms of non-metallic fibers on concrete’s compressive strength, tensile strength, flexural strength, and durability performance. The findings indicate that non-metallic fiber concrete exhibits superior mechanical properties and durability. This article presents a theoretical foundation for the design and utilization of non-metallic fiber concrete.

Вестник Полоцкого государственного университета. Серия F. Строительство. Прикладные науки

Designing frequency cross-over is important for loudspeakers to gain better control, reduce distortion, and improve efficiency. Engineers have introduced the DSP-based digital feedback FIR filter to overcome the drawbacks of analog cross-over, such as intermodulation distortion (ID) and transient intermodulation distortion (TIM). However, the digital feedback loop introduces an additional time delay (TD) and phase shift that lowers the system’s stability and elongates the relaxation time, decreasing the damping factor and the total gain. Using the deep neural network (DNN) can overcome these disadvantages. With machine learning algorithms like backward propagation, DNN can model the nonlinear response of the system and compensate them to obtain better control of the speaker with less gain loss. This work simulates a frequency cross-over using DNN and compares it to the open loop and FIR direct digital feedback amplifier (DDFA) systems. Our simulation shows that the DNN filter can approach the best filter result (FFT filter). With nonlinear load, the DNN filter can function as both frequency cross-over and distortion compensator with a great nonlinearity suppression with a time constant of 0.05 while the DDFA of 0.11 and the open loop of 0.32. The overall gain of the DNN filter (1.13) is close to the open loop (1.1) and better than the DDFA (1.25). With such superiority, DNN-based cross-over will be a good platform for designing the next-generation cross-over.

This paper adopts a contrastive experimental method to design and prepare reed fiber concrete. It discusses the influence of reed fiber content (2%), fiber length (1.5 cm for short reed fiber and 3 cm for long reed fiber), and moisture content (0% for dry fiber and 85% for wet fiber) on the mechanical properties of concrete, and compares it with the reference concrete without reed fiber. The experiment obtained the flexural and compressive strength of reed concrete, and analyzed the apparent mechanism of concrete specimens after failure. The experimental results show that the addition of reed fiber enhances the mechanical properties of concrete, the compressive strength of concrete increases by 1.13 MPa compared with the reference concrete, and the flexural strength increases by 2.32 MPa. The flexural performance of reed fiber reinforced concrete with 3 cm dry fiber and 0% moisture content is the highest, reaching 3.5 MPa; the compressive performance of reed fiber reinforced concrete with 85% moisture content and short reed fiber is the highest, reaching 2.69 MPa. This paper shows that adding 2% of reed fiber to concrete is feasible, and adding 1.5 cm, 85% moisture content wet reed fiber can better promote the mechanical properties of reed fiber concrete.

The field of carbon fiber–reinforced concrete (CFRC) with shell aggregates is attracting attention due to the demand for sustainable and high‐performance building materials, particularly, this topic is important for seeking to fill a gap in the literature regarding the combined use of carbon fibers (CFs) and shell concrete. Specifically, in this field, developing a composite material that addresses the brittleness and environmental impact of traditional concrete while improving its strength and durability is cutting‐edge; however, the amount of fiber and shellfish added is still under debate. To answer the question, this study explored the synergistic effects of CFs and shell aggregates on concrete’s mechanical properties and sustainability by employing an orthogonal experimental design. This method integrated CFs and shell aggregates into the concrete mix, replacing 50% of the traditional coarse aggregates with shells and adding CFs at rates of 0.5%, 1%, and 1.5%. Various mechanical tests assessed improvements in tensile strength, flexural strength, crack resistance, and overall durability. Additionally, the environmental impact and sustainability benefits of these materials were evaluated to identify the optimal combination for maximizing both performance and sustainability of the composite material.