Research Transcripts in Materials

Use of Construction and Demolition Waste Material for Soil Stabilization

2024-03-03T16:59:07+00:00

Soil stabilization is the method of modifying and improving soil engineering properties. Properly stabilized soil exhibit better bearing capability, shear strength, density and lower permeability, plasticity and shrink-swell characteristics. Soft and expansive soil is grave threat to the existence and safety of the structures constructed over and underneath it. The availability of a suitable stabilizer, which can modify and strengthen the characteristics of weak soil, is vital for the safety and longevity of the structures. It is essential to use such a stabilizer which is cheap, easily available and environment-friendly. Construction and demolition (C&D) debris are solid wastes accessible at construction sites at nominal cost. This study mainly investigates the changes in the soil behaviour, precisely the strength characteristics, on mixing the C&D wastes by replacing the original soil with 5%, 10%, 15% and 20% of the C&D debris respectively. The results demonstrated that up to certain extent the strength characteristics improved. The C&D debris utilization can help in environmental protection and prevention of land and water pollution, which can contribute towards the goal of sustainable development.

Application and Performance of RAP in Highway Construction: A Literature Review

2024-03-03T17:23:34+00:00

Reclaimed Asphalt Pavement (RAP) is degraded asphalt that has been removed from damaged flexible pavement. The second-largest road network in the world, with a length of more than 63.72 lakh km, is found in India, according to the MoRTH's annual report for 2021–2022. Large quantities of RAP are produced each year during highway maintenance and construction. When the flexible pavements are removed for reconstruction or resurfacing, they are dumped in landfills, posing serious environmental concerns. Recycling overcomes the exploitation of natural resources, reduces the unwanted increase of road elevation due to periodical overlays, and disposal of RAP generated from pavement construction. An overview of the application of RAP is provided in this publication, to understand its importance and performance in highway construction when mixed with different materials viz. rejuvenators, nanomaterials, WMA additives, reinforcement with polymer or bamboo, fly ash – lime, etc. The use of recycled asphalt pavement is progressively expanding in India for road building, which meets the overall goal of sustainable development by lowering the consumption of natural resources, the emission of hazardous gases, the cost and energy of disposal, and landfill utilization.

Static Load Response of Laminated Composite Stiffened Cylindrical Shell Using Finite Element Analysis

2024-03-03T17:30:05+00:00

Laminated composites, a contemporary material, are widely used as a roofing option in civil engineering. They have benefits such as a lower weight-to-strength ratio, durability to harsh weather, and customizing options. However, researchers have expressed concern about the restricted transverse shear capacity, which can result in delamination under extreme strain, which is often confined inside the layers and eventually causes collapse. To overcome this, cylindrical shells are typically supplied with stiffeners to withstand static pressure deformation. There is a dearth of extensive research on the behaviour of laminated composite stiffened cylindrical shells under static loads in the existing literature. The purpose of the study is to investigate the behaviour of laminated composite stiffened cylindrical shells in terms of total deformation, maximum principal stress, and maximum principal strain caused by static pressure. On both simply supported and clamped two-ply laminated cylindrical shells, various stiffener sites are investigated. The stacking sequences are changed to compare the parameters mentioned. This study conducts a parametric investigation to draw engineering-relevant conclusions using ANSYS. According to the study's conclusion, the inclusion of differentially organized stiffeners results in a reduction in deformation, stress, and strain levels.

Review on the Importance of Coarse Recycled Concrete Aggregates as Alternative Construction Materials

2024-03-03T17:37:51+00:00

Recycled concrete aggregates are one of the most important supplementary building materials used in the production of "green concrete" or recycled aggregate concrete. They are collected from construction and demolition trash, which decreases construction industry waste (RAC). By size, aggregates are divided into coarse and fine aggregate. Focus of research is on the replacement of coarse aggregate in concrete using coarse recycled concrete aggregate (CRCA). It is vital to provide a major overview on the main developments and advancements in the characterization of CRCA and in the comprehension of the behaviour of concrete containing this, taking into account its varied attributes such as freshness, hardness, and durability. Because of the weak attached mortar present on its surface, CRCA's performance in all areas falls as the replacement percentage rises. Different treatments such as washing and drying of aggregate, changed mixing sequences, carbonation, slurry and microbiological treatments, CO2 mineralization and air jigging process can mitigate the negative effects of CRCA in the concrete. This study discusses the issues raised by the widespread use of CRCA on concrete and the effectiveness of the numerous treatment solutions that are now available in the industry.

Performance Evaluation of Light Transmitting Concrete Made with Plastic Optical Fibers

2024-03-03T17:45:38+00:00

Light transmitting concrete (LTC) is a concrete made with light optical elements (e.g., plastic optical fibers) having the light transmitting property. In addition to its use as aesthetic purpose, LTC enhances the utilization of natural resource by the projection of light through the concrete. Thus, this translucent concrete can be used in structures to make energy efficient and environment friendly structures through the minimization of artificial energy usage. This chapter deals with the performance evaluation of light transmitting concrete (LTC) made with plastic optical fibers (POFs). For this purpose, compressive strength and light transmitting properties of LTC have been investigated and compared with conventional concrete. Experimental results show that the compressive strength at 7 days, 14 days, and 28 days have been increased by 3.47-12.23%, 4.82-14.85%, and 4.07-9.78%, respectively for the LTC made with various percentage of POFs. From the simple light transmission test, it has been found that the LTC made with 0.75 mm, 1 mm, and double layer 0.75 mm POFs can transmit 8%, 9.44%, and 14.8% light, respectively. Results of the present study imply that light transmitting concrete made with POFs can be used for aesthetic and energy saving purpose without compromising the strength.

Effect of Water to Geopolymer Solids Ratio on Properties of Fly Ash and Slag-Based One-Part Geopolymer Binders

2024-03-03T17:59:08+00:00

Geopolymer binders are claimed to be a satisfactory substitute for ordinary Portland cement (OPC) nowadays. These binders showcased their impracticalities in the execution part concerning transport, storage, and handling of strong alkaline solutions. This study describes a new "one-part" or "just add water" geopolymer binder which can be made in the same way that OPC is made by dry-mixing solid alumina-silica-rich materials, solid alkali activators, and free water. The flowability and compressive strength of one-part geopolymer binders produced from fly ash and slag were investigated as a function of the water to geopolymer solids (W/GS) ratio in this study. The W/GS ratio was considered as 0.25, 0.30, and 0.35. At each level of W/GS ratio, 25%, 50%, and 75% of the fly ash was substituted with ground granulated blast furnace slag by weight, where the solid activator content was maintained at 12% for all the mixes. The experimental and microstructural observation shows that the 50/50 fly ash/GGBS mixture at 0.30 W/GS had the best flowability and compressive strength, and their microstructure exhibited signs of being dense and compact compared to the other mixtures.

Impact Response of Laminated Composite Simply-Supported Stiffened Conoidal Shell With Cut-Out

2024-03-03T18:06:30+00:00

Laminated composite has become popular in the weight sensitive branches of engineering. In recent times it is widely used in civil engineering as roofing entity. It has advantages like low specific weight, high specific strength, weathering resistance and can be tailored as per the user. Despite these advantages low transverse shear capacity under impact loading compelled researchers to conduct further research for its successful implementation industrial sectors. Impact, which is likely to occur in cyclone prone zones and aircraft bases where wind borne debris causes the same. Impact causes delamination, cracks in epoxy medium or tearing of fibers which remains suppressed under lamina and causes eventual failures. Conoidal shells used as roofing entity is often provided with cut-outs for accommodation of utilities. Concentration of stresses in discontinuous edges may cause unacceptable deformation and stress concentration. Stiffeners become unavoidable in certain cases to lower the stress generated around cut-outs. Incorporation of proper contact law is important for impact analysis. Literature survey reveals that conoidal shell is an interesting roofing entity and needs to be studied for its confident application. Present study is an effort to investigate the impact behaviour of such conoidal shell roof.

Statistical Review of Bamboo's Mechanical Properties for Building Applications

2024-03-03T18:17:00+00:00

Materials which are high yielding and sustainable are now being researched to serve human demands because of rising global expansion and unfriendly utilization of raw materials. Bamboo is a rapidly growing, long-lasting material that may be used to satisfy most human requirements (such as housing, nourishment, and equipment). With scientific discoveries, innovation and knowledge, humankind is revisiting several habits and reverting to some more traditional approaches and techniques that are beneficial to human wellbeing, ecological and overall sustainable development in the 21st century. This study primarily emphasizes how to utilize bamboo for technical purposes, driven by these ecological issues. To begin, a material should be damagingly evaluated to obtain physical property before it can be used in engineering and construction projects. As a result, a thorough review of the existing literature on bamboo mechanic property values was studied. It was discovered that combining physical properties of every property and linking the variation in property values with bamboo characteristics shows that bamboo is the most suitable green material.