Nasir Mahmood Khan

The sustainable development of materials is one of the key targets in the modern era of engineering. These materials are developed by different waste products, following the concept of the circular economy. This study focuses on investigating the properties of concrete using carbon black as a partial replacement of natural fine aggregate at different percentages. Experiments were designed according to the British Standard (BS1881-Part-119) and American Standard (ASTM C-78) by including carbon black in concrete beams to perform as filler material to develop sustainable concrete. In this study, mechanical properties of concrete were targeted by developing beams using different percentages (0%, 25%, 50%, 75%, and 100%) as a replacement of fine aggregates. These beams were tested for flexural strength and, later on, the same beams were cut in the form of cubes, following the equivalent cube test mechanism for the compressive strength test. The waste carbon black lightweight concrete developed in this study was utilized for both structural and non-structural purposes. At 25% and 50% replacement, the strength of lightweight concrete varied from 20–18 MPa, and according to American Concrete Institute (ACI) standards, lightweight concrete at 28 days strength with ≥17 MPa can be used as structural concrete, and the remaining 75% and 100% replacement concrete can be used for non-structural purposes. This study will help in the development of economical eco-friendly sustainable concrete materials.

Sustainable engineering practices always provide an opportunity for engineers to produce long-term solutions. In the fields of construction and irrigation, soil bed formation symmetry is very important, especially in the case of its behavior with reference to water runoff, whether natural or artificial. In this study, different soil bed formations were tested with the help of advanced hydrology apparatus under severe rainfall conditions. A major focus was to observe the water retention and volume discharge with reference to soil combinations and slope level change. Furthermore, an advanced decision-making technique incorporating artificial neural networks (ANNs) was used to predict and explore the interrelationship behavior of different parameters. It was observed that ST-1 (100% clay) performed well as it tried to retain a large quantity of water (7.28 L/min), making it suitable for irrigation, while ST-2 (100% sand) performed better for structures, as sand tries to quickly drain water, thus retaining less water (0.16 L/min). Change of slope was also another factor; at a 3% slope level along with 100% clay, water resistance was higher as compared to sand. Soil type-3 (ST-3) helped in the retention of water even at a 3% soil bed slope. This study will help engineers and designers in the optimization of soil bed formation for construction and irrigation purposes.

This research dealt with the impact of the quality of the water source on the mechanical properties of construction materials. The mechanical properties of construction materials include compressive, tensile, and flexural strength. Water samples were collected from different resources, these samples were then synthetically investigated to identify and compare their quality parameters. After a detailed chemical analysis of water samples from three sources—wastewater, surface or canal water, and ground water—construction concrete material samples were prepared. The construction materials were developed with the same water–cement ratio, i.e., 0.60 for each concrete mix sample at two mix ratios—M1 (1:2:4) and M2 (1:1.5:3). Slump cone and compacting factor tests were conducted on the fresh concrete to determine its workability prior to its hardening. Then, at 7, 14, 21, and 28 days for each mix, tests for mechanical properties were carried out to determine the compressive, tensile, and flexure strengths. Results showed that the mechanical properties of the concrete made by utilizing wastewater and surface water were more noteworthy as compared to the concrete made by groundwater. This study will help in the production of concrete which depends on waste and surface canal water, even for large projects like rigid pavement construction and water-related structures.