Response tests on the effects of particle size of waste glass sand and glass powder on the mechanical and durability performance of concrete.

To investigate the effect of waste glass material particle sizes on the mechanical and durability properties of concrete, a two-phase experimental approach was conducted. First, comprehensive tests were performed to examine the effects of glass sand and glass powder of different particle sizes on concrete performance. Subsequently, based on the experimental results, an orthogonal test was designed to optimize the replacement amounts of composite particle sizes.

Experimental study on recycling rubber to increase the impact resistance of cement mortar.

The COVID-19 pandemic has led to a surge in medical waste generation, posing hazards to both the environment and global health. The impacts of the COVID-19 pandemic's medical waste hazard may persist long after the pandemic itself subsides. Improper disposal of medical waste can contaminate environment, posing risks to ecosystems and public health.

Erosion degradation analysis of rice husk ash-rubber-fiber concrete under hygrothermal environment.

To study the resistance of rice husk ash-rubber-fiber reinforced concrete (RRFC) to dry-wet cycle/chloride erosion under a hygrothermal environment, the optimal combination was selected by an orthogonal test. The peak strain, residual strain, and fatigue damage strength of the optimal group of RRFC samples under cyclic loading and unloading after dry-wet cycle/chloride erosion under different environments and temperatures were compared and analyzed. After that, microscopic analysis and anti-erosion mechanism analysis were carried out.

Study on static and dynamic mechanical properties and microstructure of silica fume-polypropylene fiber modified rubber concrete.

Through tests and micro-observations, the static and dynamic mechanical properties and microstructure of rubber concrete samples modified with varying amounts of silica fume and polypropylene fiber content were explored. The results indicate that incorporation of silica fume and polypropylene fiber can effectively enhance the performance of rubber concrete. Moreover, at 10% and 0.

Variable angle of insulated shotcrete under different loading rates and temperature and humidity cycles- shear test and analysis.

The new thermal insulating shotcrete is of great significance for the management of thermal damage in deep mines, and its own strength has a greater impact on the roadway insulation and safe production, so it is very necessary to study the shear strength of the new thermal insulating shotcrete under the influence of the deep hot and humid environment and the stress of mining. For the heat-insulating shotcrete, firstly, we carried out the concrete variable angle shear test under different loading rates, which concluded that the shear rate and peak shear stress showed a trend of increasing and then decreasing; as the angle increases, the different rates have a greater impact on the peak shear stress of the specimen. Secondly, the concrete variable angle shear test was carried out under the temperature and humidity cycle, which revealed that the shear strength of thermal insulated shotcrete increased firstly and then decreased with the increase of temperature at the same number of cycles.

Research and development of fully enclosed wire-shell support structure technology for deep soft rock roadway based on TRIZ theory.

The TRIZ theory was used to accurately discover the problems to be solved in the design of roadway surrounding rock control technology. This paper tried to solve the complex issue of surrounding rock control in deep roadways from a new perspective. Based on the functional component analysis and causal axis analysis of the problem's primary reason, simultaneously, the surrounding rock control technology was optimized through technical contradiction analysis, physical contradiction analysis, and substance and field model analysis.

Mechanical Properties and Microstructure of Rice Husk Ash-Rubber-Fiber Concrete under Hygrothermal Environment.

In order to study the mechanical properties of rice husk ash-rubber-fiber concrete (RRFC) under hygrothermal environment, the optimal group was selected by orthogonal test. The mass loss, relative dynamic elastic modulus analysis, strength analysis, degradation degree analysis after cyclic loading and internal microstructure analysis of the optimal group of RRFC samples after dry-wet cycles under different environments and temperatures were compared and analyzed. The results show that the large specific surface area of rice husk ash optimizes the particle size distribution of RRFC specimens, reacts to form C-S-H gel, enhances the compactness of concrete, and forms a dense structure as a whole.

Performance of Rubber Concrete Containing Polypropylene and Basalt Fibers under Coupled Sulfate Attack and Freeze-Thaw Conditions: An Experimental Evaluation.

Rubber concrete (RC) is a new type of concrete that is currently receiving a lot of attention, solving serious pollution problems by grinding waste tires into granules and adding them to concrete. However, rubber concrete has deficiencies in mechanics and durability, and has been reinforced by adding fibers in many studies. In this study, the mechanical and durability properties of rubber concrete with added polypropylene and basalt fibers (PBRC) were investigated in a series of experiments including apparent morphology, mass, static compressive and tensile tests, ultrasonic non-destructive testing, and scanning electron microscope (SEM) tests under coupled environments of sulfate attack and freeze-thaw.

Influence of Basalt/Polypropylene Fiber on Permeability and Uniaxial Compressive Properties of Waste Tire Rubberized Concrete.

The rubber particles obtained from the grinding of waste tires can replace a portion of the fine aggregates in concrete, thus effectively reducing the level of environmental damage and saving resources. However, when concrete is mixed with rubber, it greatly reduces its strength. In this study, by introducing basalt fiber (BF) and polypropylene fiber (PF) as modified materials in rubberized concrete, the influence of the fiber type/volume ratio on the slump, water absorption, static uniaxial compression, and permeability of the rubberized concrete was tested.

Performance degradation and damage model of rice husk ash concrete under dry-wet cycles of sulfate environment.

Rice husk ash concrete (RHAC) is a new type of concrete that has been rapidly gaining acceptance in recent years. In this paper, the improvement effect of rice husk ash (RHA) on the sulfate erosion performance of concrete was confirmed. The ratio of rice husk ash concrete (RHAC) was optimized and compared with ordinary concrete (OC).

Experimental Study on the Influence of Rubber Content on Chloride Salt Corrosion Resistance Performance of Concrete.

In order to enhance the corrosion resistance of concrete to chloride salt, 5% NaCl solution was used to corrode ordinary concrete (OC) and rubber concrete (RC) with 5%, 10%, and 15% rubber content, respectively. By testing the compressive strength, mass, chloride ion concentration at different depths and relative dynamic elastic modulus, the erosion mechanism was analyzed by means of SEM scanning and EDS patterns, and the mechanical properties and deterioration degree of ordinary concrete (OC) and rubber concrete (RC) under the corrosion environment of chloride salt were studied. The results show that: the quality of rubber mixed into concrete increases first and then decreases, and rubber can increase the compressive strength of concrete, improve its internal structure.

A Research on Durability Degradation of Mineral Admixture Concrete.

In order to study the degradation laws and mechanisms of admixture concretes with single-added SO and composite of Mg and SO, respectively, the durability tests were conducted on three types of mineral admixture concretes (concretes with single-added metakaolin (MK), single-added ultra-fine fly ash (UFA), and composite of metakaolin and ultra-fine fly ash (MF), and one reference concrete. In these tests, the 10% NaSO solution and the 10% MgSO solution were used as the erosion medium, and the drying-wetting circle method was applied. It can be seen from the compressive tests and grey relational analysis that the MK admixture can improve the anti-NaSO-erosion capability of the concrete significantly, but weaken its anti-MgSO-erosion capability; the UFA admixture can improve both the anti-NaSO-erosion and the anti-MgSO-erosion capability of the concrete; and the composite admixture has superimposed effects and can enhance erosion resistance against these two erosion mediums.

Effects of High Temperature on Creep Behaviour of Glazed Hollow Bead Insulation Concrete.

Glazed hollow bead insulation concrete (GHBC) presents a promising application prospect in terms of its light weight and superior fire resistance. However, only a few studies have focused on the creep behaviour of GHBC exposed to high temperatures. Therefore, in this study, the mechanism of high temperature on GHBC is analysed through a series of tests on uniaxial compression and multistage creep of GHBC, exposed from room temperature up to 800 °C.

Performance Degradation and Microscopic Analysis of Lightweight Aggregate Concrete after Exposure to High Temperature.

This study analyses the deterioration of mechanical properties in lightweight concrete after exposure to room temperature (20 C) and high temperature, i.e., up to 1000 C, including changes in visual appearance, loss of mass, and compressive strength.