Mechanical and Microstructural Analysis of Waste Ceramic Optimal Concrete Reinforced by Hybrid Fibers Materials: A Comprehensive Study

Combining different types of fibers inside a concrete mixture was revealed to improve the strength properties of cementitious matrices by monitoring crack initiation and propagation. The contribution of hybrid fibers needs to be thoroughly investigated, considering various parameters such as fibers type and content. The present study aims to carry out some mechanical and microstructural characteristics of Waste Ceramic Optimal Concrete (WOC) reinforced by hybrid fibers. Reinforcement materials consist of three different fiber types: hook-ended steel fiber (HK), crimped steel fiber (CR) and polyvinyl alcohol (PVA) fibers and the effect of their addition on the waste ceramic composites’ mechanical behaviour. Furthermore, a microstructural analysis was carried out to understand the waste ceramic matrix composition and its bonding to hybrid fibers. Results showed that the addition of hybrid fibers improved the strength characteristics of the ceramic waste composites. For instance, the existence of PVA-CR increased the tensile and flexural strength of the waste ceramic composite by 85.44% and 70.37%, respectively, with respect to the control sample (WOC). As well as hybrid fiber exhibits improved morphological properties as a result of increased pore filling with dense and compact structure, as well as increased C–H crystals and denser structure in pastes as a result of the incorporation of hybrid fibers into the concrete mix. The present experimental research shows the choice of using steel fiber with PVA as a reinforcement material. The idea of adding hybrid fiber is to prepare the economic, environmental, and technological concrete. Moreover, it offers a possibility for improving concrete’s durability, which is vital. Finally, it was concluded that steel fiber is more durable, and stiffer and provides adequate first crack strength and ultimate strength. In contrast, the PVA fiber is relatively flexible and improves the post-crack zone’s toughness and strain capacity

Destructive and Non-Destructive Evaluation of Fibre-Reinforced Concrete: A Comprehensive Study of Mechanical Properties

Ultrasonic pulse velocity (UPV) and rebound hammer tests are accepted as alternatives to destructive testing to determine the compressive strength, dynamic modulus of elasticity, and Poisson's ratio, which are needed for structural design. Although much work has been conducted for plain concrete, the research data for fibre-reinforced concrete (FRC) is insufficient. In this regard, this study explains the correlations between compressive strength, rebound hammer, and UPV tests for plain concrete and FRC contains 0.25%, 0.50%, and 1.00% of 30 mm and 50 mm long steel fibres. A total of 78 concrete cube and beam specimens were tested by direct, semi-direct, and indirect UPV and rebound hammer test methods. The study found that the rebound hammer test is more suitable for measuring the compressive strength of matured FRC than young concrete. The UPV test revealed that the volume fraction does not, but the length of steel fibres does affect the UPV results by the direct test method. The UPV direct method has the highest velocity, approximately two times the indirect velocity in FRC. UPV measurements can be effectively used to determine the dynamic modulus of elasticity and Poisson's ratio of FRC. The dynamic elastic modulus increases while the Poisson's ratio decreases for the same steel fibre length when at increasing FRC fibre content. The results of this study will be significant for non-destructive evaluations of FRC, while additional recommendations for future studies are presented at the end of the paper

Leadership development and sustainable leadership among TVET student

Leadership has become a key component of an organization, management and administration of educational organizations and systems, and this development is reflected in both academic and educational policy statements throughout the English-speaking countries and world over. Governments are investing substantial sums in leadership development because they believe that it will produce better leaders and more effective school system. Individuals are also contributing their own professional development because they think that it will enhance their career prospects and make them better leaders. Without leadership, things will be very difficult and we would have not been here today. Technical and vocational education is one of the organizations that have been enjoying leadership of different types. The importance of leadership in technical and vocational education cannot be overemphasizing, because without proper leadership in TVET programs, the goals which are to prepare people to be self-reliance will not be possible. Therefore, the need for good and perfect leadership has become imperative in TVET development. Effective school leadership has become a dominant theme in contemporary educational reform. Effective leaders are needed to sustain innovation and are the heart of capacity building for school improvement most especially in technical and vocational education and training (TVET) programs that need sustainability for its development

Colour Change of Sustainable Concrete Containing Waste Ceramic and Hybrid Fibre: Effect of Temperature

Construction and demolition (C&D) waste was considered as zero value materials and, as a result, most C&D waste materials ended up in landfills, eventually constituting environmental issues. Therefore, it is important to explore the potential of such C&D waste materials for concrete production. Thus, this research effort aims to find a new method to improve sustainable concrete properties exposed to elevated temperatures at the lowest costs and identify the relationship between temperature change and a change in colour in a heat-exposed concrete structure. Therefore, this study explored the behaviour of three types of concrete: plain concrete (PC), waste ceramic optimal concrete (WOC), and waste ceramic optimal concrete reinforced by hybrid fibre (WOC-Hybrid) in ambient and elevated temperature. The study shows that colour change in a concrete structure exposed to high temperature has a consistent relationship, where it has been found that the colour alteration is of great interest because its appearance usually coincides with the onset of a significant loss of concrete strength as a result of elected temperatures. Overall, it can be considered that waste ceramic materials reinforced by hybrid fibres can be used for concrete production, and by doing so, the negative impact of these wastes on the environment can be controlled as well as fortify the mechanical properties

Mechanical Properties, Crack Width, and Propagation of Waste Ceramic Concrete Subjected to Elevated Temperatures: A Comprehensive Study

Waste ceramic concrete (WOC) made from waste ceramic floor tiles has several economic and environmental benefits. Fire is one of the most common disasters in buildings, and WOC is a brittle construction material; therefore, the mechanical properties of WOC structures under high temperatures should be considered. According to previous studies, hybrid fiber can further reduce damage to concrete under high temperatures. Meanwhile, crack width and propagation are among the key characteristics of concrete materials that need to be considered, but few studies have focused on their behavior when subjected to elevated temperatures. The new concrete materials proposed by the authors are WOC and WOC-Hybrid. WOC was prepared with Natural Coarse Aggregates (NCA), Natural Fine Aggregate (NFA), Ordinary Portland Cement (OPC 43 grade), and ceramic waste tiles with 20% replacements for coarse aggregates, 10% replacements for fine aggregates, and 10% replacement for cement. In contrast, WOC-Hybrid was prepared with the addition of hybrid fiber (1% crimped steel fiber and 1% polyvinyl alcohol fiber) in WOC. The specimens were exposed to temperatures of 100-300 °C, and then the specimens were tested for tensile and compressive strength. The present study aims to find a new method to improve concrete resistance to elevated temperatures at the lowest costs by experimental and computational analysis via machine learning models. The application of machine learning models such as artificial neural networks (ANN) and multiple linear regression (MLR) was employed in this study to predict the compressive and tensile strength of concrete. The linear coefficient correlation (R2) and mean square error (MSE) were evaluated to investigate the performance of the models. Based on the experimental analysis, the results show that the effect of hybrid fiber on the crack width and propagation is greater than that on the crack width and propagation of WOC and PC after exposure to high temperatures. However, the enhanced effect of hybrid fiber on the mechanical properties, rack width, and propagation decreases after subjecting it to a high-temperature treatment, owing to the melting and ignition of hybrid fibers at high temperatures. Regarding the computational analysis, it was found that the developed MLR model shows higher efficiency than ANN in predicting the compressive and tensile strength of PC, WOC, and WOC-Hybrid concrete

Sustainable lightweight foamed concrete using hemp fibre for mechanical properties improvement

Fibres have long been used as an additive in the fabrication of building elements and materials. A combination of natural and synthetic fibres has shown promise in preliminary research and testing, with the added benefit of greatly improved strengths of the composites. Compared to traditional reinforcement bars, natural fibre reinforcement's ratio of fibre required is significantly lower, making it more beneficial in terms of energy and economic values. Recent research has focused on the feasibility of using both natural and synthetic fibres as reinforcement in concrete and other construction materials. Thus, the purpose of this research is to investigate the feasibility of using hemp fibre at various percentages (0%, 0.2%, 0.4%, 0.6%, and 0.8%) as an additive in lightweight foamed concrete to enhance mechanical properties. Three LFC densities namely 500, 900 and 1300 kg/m3 were fabricated and tested. Axial compressive strength, flexural strength, splitting tensile strength, and ultrasonic pulse velocity were the four mechanical parameters that were assessed. The findings demonstrated that adding 0.4-0.6% of HF to LFC produced the best results for ultrasonic pulse velocity, compressive strength, flexural strength, and splitting tensile strength. The HF is essential in assisting to stop the spread of cracks in the plastic state of the cement matrix after the load was applied

Durability Properties of Lightweight Foamed Concrete Reinforced With ‘Musa Acuminate’ Fibre

The demand for lightweight building materials that are easy to work with, self-compacting, and environmentally friendly has been acknowledged by the construction industry globally. Given this demand, it has been discovered that a recent innovative material, lightweight foamed concrete (LFC), may be able to reduce the weight of ordinary concrete. Besides, utilizing LFC with the addition of natural fibres is seen as a great effort to assist sustainability. Corrosion of reinforcing steel, which affects the behaviour and longevity of concrete buildings, is one of the most significant challenges in the construction of reinforced LFC. Therefore, the focus of this work is on identifying the possible application of Musa Acuminate fibre (MAF) in LFC. The intention of this study is to ascertain the durability characteristics of LFC with MAF. The cast has a low density of 550 kg/m3. We'll employ several volume fractions of MAF that are 0.15%, 0.30%, 0.45%, and 0.60%. The ability to absorb water, porosity, drying shrinkage and ultrasonic pulse velocity are the four criteria that will be evaluated. For the purpose of creating the necessary density of LFC, the protein-based foaming agent Noraite PA-1 was used. A constant water-to-cement ratio of 0.45 and a constant cement-to-sand ratio of 1.5 were used to get comparable results. The findings showed that for all of the durability attributes taken into account in this research, an increase of 0.45% MAF produced the best results. This resulted from the MAF and LFC cementitious composite's better bonding performance. Additionally, the fibres served as an anti- micro crack, preventing LFC cracks