In this paper, foam concrete was produced using gypsum material at a dosage of 500 kg/m3 as binder and 75 kg/m3 of foaming agent, and gypsum-based colored foam concrete (GBCFC) with dry unit weights below 1100 kg/m3 was obtained by using 5% coloring pigment during the production phase. Fresh state, physical, mechanical and high temperature resistance properties of the produced GBCFCs were tested. The spread diameters of the produced GBCFCs vary between 173 and 155 mm. 28-day compressive strengths vary between 7.8 and 2.7 MPa. Capillary water absorption values vary between 3.2 and 2.2 kg/m2. The weight loss after high temperature varies between 4.86 and 21.57%, while the compressive strength varies between 6.9 and 0.2 MPa. In the production of foam concrete to be used for wall and roof insulation, decorative panels and fire prevention, etc., the use of gypsum instead of cement as a binder and the coloring process during the production of foam concrete with pigment reduces the costs and the amount of CO2 emitted to nature, providing an economically positive and environmentally friendly composite production. The process of coloring this composite with pigment during the production phase has been proven by laboratory experiments to have positive effects in terms of workability and positive contributions in terms of mechanical and some durability properties.

This paper presents the basis of a new modeling approach of the concrete/steel bond. This approach has for objective to consider the macrocrack propagation through the steel rebar and the sliding along this rebar due to concrete microcracking. Concerning the macrocracks propagation a probabilistic semi-explicit cracking model is presented. This model integrates damage and linear fracture mechanics theories. Concerning the non-linear behaviour along the rebar, a very simple deterministic damage model is presented. A simple layer of volume elements is used to model the bond zone. Numerically speaking, it is proposed to use an implicit algorithm with linear volume elements. This paper presents also the different procedures to determine the values of all the parameters involved in the proposed models.

The engineering properties of high-strength concrete are significantly different from those of ordinary concrete, and as a result, this concrete has become popular in a variety of applications, including the construction industry, particularly for tall buildings, bridges with long spans, and precast members. Reinforcing high-strength concrete using fibers is a common method for increasing ductility without losing strength. In this study, steel fibers were employed to replace 1, 1.5, 2, and 2.5 percent of the total volume of concrete, and a total of 5 mixed designs were conceived and constructed. The findings showed that the addition of steel fibers up to 2% by volume boosted the compressive strength and decreased at 2.5% by volume. The incorporation of steel fibers has diminished the mixes' durability.

The low strength of lightweight aggregates diminishes the strength of lightweight concrete, and the concrete's fragility impedes the ductile behavior of structures subjected to seismic stresses. The use of reinforcing materials and fibers may increase the strength of lightweight concrete by compensating for the impact of reduced strength caused by the use of lightweight particles and preventing the rapid breakdown of concrete. The performance of the materials used is an effective determinant of structural member behavior. Therefore, for computational analysis of finite elements to accurately anticipate the behavior of structural parts, precise behavioral models of materials are required. This study studied the tensile behavior of lightweight structural concrete containing steel fibers (at a volume percentage of 1%) and nanosilica reinforcing pozzolan (at a weight percentage of between 1 and 3%), using tensile strength as one of the influencing factors. together with the strain corresponding to the maximal stress. The inclusion of steel fibers and nanosilica had the largest influence on enhancing the tensile behavior of lightweight concrete, according to the data. By adding 3% nanosilica and 1% steel fibers to light concrete, the direct tensile strength has risen by 74%. In addition, the indirect tensile strength is somewhat greater in all samples than the direct tensile strength.

In terms of the impact of human activity on the natural environment, civil engineering is one of the most significant productive pursuits. The production and use of building materials, the advancement of engineering and construction, the use of the project after it is completed, the removal of discarded components, and other procedures all require significant energy expenditure and ongoing waste generation, which can have severe consequences for the natural environment. To meet the demands of both economic and social development, advancements in civil engineering must be made while also protecting the natural world, limiting the use of natural resources, and promoting sustainable development. This study examines the long-term strategy in civil engineering and explores the role of environmental sustainability throughout the various stages of the civil design process, including the conceptual stage, the technical design stage, and the building stage. The research finds that the construction industry should adopt practices that adhere to sustainability principles such as environmentally-friendly design, durability, energy efficiency, waste reduction, improved indoor air quality, water conservation, and the use of sustainable building materials in construction.

Lately, because of the pollution caused by cement production waste materials that can be used instead of cement aroused interest by researchers. Glass is one of these waste materials. Glasses due to their nonbiodegradable properties, cause serious environmental risks and recycling this waste material would minimize these environmental concerns. Therefore, finely granulated glass powders, due to their high silicious content are being used as pozzolanic admixture. In this study, glass powders are replaced with cement (by weight) at 0%, 5%, 10% and 15%. And mechanical and durability performances are investigated. Compressive and flexural strength, flow test, abrasion resistance, sulfate resistance and capillary water absorption test were conducted. Results indicated that an increase in glass powder dosage in cement mortars leads to decrease in mechanical properties.

Kaolin, also known as China clay, is one of the materials that can be used as partial replacement for Portland cement but most of the research has been focused on its dehydroxylated form (metakaolin). The lack of interest in raw kaolin clay as a cement replacement material is partly due to its negative impact on strength and the traditional perception that raw clay is detrimental to concrete. However, the use of raw kaolin clay as cement replacement may offer other benefits, such as energy saving and the potential to produce durable cement-based material at low cost. Therefore, this paper presents findings on the influence of raw kaolin clay on the properties and durability performance of Portland cement mortar in comparison with metakaolin, when used as partial substitute. The results show that the use of raw kaolin clay as a partial substitute for Portland cement improved all aspects of the durability properties investigated, which became more apparent with age. Despite having the lowest compressive strength, the raw kaolin clay mix displayed a lower porosity, better resistance to water absorption and finer pores than the control. In contrast to the raw kaolin clay, the metakaolin significantly enhanced both strength and durability. The results also reveal that at a given superplasticizer dosage and replacement level, the kaolin and metakaolin mixes exhibited the same consistency in the fresh state and a similar range of pore size distribution and total intrusion volume at 28 days. The findings further demonstrate that raw kaolin clay can be used as Portland cement replacement material to produce durable mortar and concrete, particularly for applications that do not require high strength.