×
The submission system is temporarily under maintenance. Please send your manuscripts to
Go to Editorial ManagerConcrete is considered the most important and widely used building material in the world of construction and building due to its durability, high efficiency in shaping, and relatively reasonable cost. The main component of concrete is cement, and one of the most important problems related to cement is the environmental problems associated with cement manufacturing, as the cement manufacturing process releases a large amount of carbon dioxide. Despite the essential role of concrete in construction, we cannot ignore its environmental impact. Some claim that exploring alternative materials or innovative building techniques would reduce the carbon footprint and enhance sustainability in the industry. Partial cement replacement with pozzolanic materials like zeolite is a key technique to reduce carbon dioxide emissions. Zeolite, which reduces permeability, is a typical concrete ingredient that strengthens and lasts. Recently, natural zeolite has become a prominent concrete pozzolanic component. For environmental preservation and sustainable development, various experiments were done on concrete with pozzolanic components partially substituting cement and compared to ordinary concrete. A partial replacement of cement with zeolite improves the properties of concrete up to a certain age and mixing ratio. More than 44 relevant articles from 2004–2024 were selected from 762 papers evaluated for this paper. This paper reviews natural zeolite research in real applications. Additionally, it provided a cutting-edge review of natural zeolite literature through a critical analysis of various previous investigations. It also helped to understand how zeolite influences concrete mixture workability, strength, and durability. Since zeolite is a major concrete ingredient, it should be promoted as a sustainable resource.
This study evaluates the performance of cement mortar incorporating micro silica (MS) and thermally treated date seed ash (DS) as sustainable partial cement replacements, in line with the demand for improved construction materials that utilize available resources. In the absence of an understanding of the behavior resulting from combining MS and DS within a hybrid replacement system particularly regarding how different blending ratios influence mortar performance and mix integrity. To achieve this, five mixtures were prepared with a total replacement level of 20% including three hybrid blends and were assessed through flowability, compressive strength, sorptivity, dry density, water absorption, and Ultrasonic Pulse Velocity (UPV) tests. Predictive models have also been developed to estimate chloride and sulfate penetration based on physical and non-destructive indicators. The results showed that the hybrid mixture MS15–DS5 demonstrated the most notable enhancement compared to the control mix, achieving a 6% increase in compressive strength a 42% reduction in sorptivity and clear increases in dry density and pulse velocity indicating a more compact internal structure. The MS10–DS10 mixture also exhibited improved behavior, though to a lesser degree. In contrast, increasing the DS content led to performance deterioration, where MS5–DS15 showed reduced strength and higher sorptivity and DS20 presented the weakest response, with an 8% reduction in compressive strength and a 32% increase in sorptivity. The predictive models also demonstrated high accuracy achieving R2 of 0.989 and 0.983 for chloride and sulfate penetration, respectively, supporting their ability to estimate future behavior based on physical properties. These results provide a clearer understanding of how combining MS and DS influences mortar behavior and mix integrity, and they contribute to the development of sustainable cementitious mixtures with improved performance when appropriate replacement levels are selected.
A rapidly expanding global population has heightened the need for engineering technologies aimed to enhancing the mechanical properties of weak soil, raising concerns about the sustainability of engineering practices that depend on energy-intensive materials and methods from earlier times. Traditional ground improvement techniques like compaction, preloading, vibration, and chemical grouting are typically costly and frequently have very high energy and CO2 footprints. Soil stabilization employing bio-enzymes has been viewed as a resilient and ecologically beneficial method for modifying the soil characteristics. Calcite-induced precipitation methods have recently become potential techniques in geotechnical engineering for improving the shear strength of soils. One of the most promising methods among them is enzyme-induced calcite precipitation (EICP). Enzyme induced calcite precipitation (EICP) is a bio-inspired technique based on the precipitation of calcium carbonate for enhancing the geo-mechanical properties of soils. In this technique, calcium carbonate acts as a cementitious agent that binds the soil particles together at the points of contact hence, increasing the strength and stiffness of treated soils, while relatively reducing the soil permeability and porosity. The achieved enhancements make EICP useful for applications such as ground improvement, construction materials, and erosion control over traditional binders. It is an environmental friendly technique that has generated great interest to geotechnical engineers. EICP particularly, has proven to be more effective since its application to all soils coarse and fine which have small pore size. This review thoroughly assesses the use of the EICP approach as a soil stabilization strategy conducted by various researchers. This review article studies urease and its implication on the characteristics of treated soil such as shear strength, permeability and micro-structural changes.