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In this investigation, the damage tolerance behavior of two different aero-engine materials i.e., GTM718 and GTM720 nickel base super alloys subjected to a turbine standard spectrum loads was experimentally determined and compared. Compact tension (CT) specimens as per ASTM test standard specifications were cut and prepared from the forged discs of these materials. Fatigue crack growth (FCG) tests were conducted using CT specimens in a 100 kN servo-hydraulic universal test machine at ambient temperature and lab air atmosphere. Constant amplitude cyclic fatigue loads were applied on CT specimen to initiate a pre-crack of about 2.0 mm in length from the notch root. Further, the fatigue crack was propagated under standard cold-TURBISTAN spectrum load sequence. The crack length was measured by compliance method as well as by using optical traveling microscope at regular intervals of completion of load blocks. Loading waveform employed during the test was triangular with a frequency of 2 Hz i.e., four reversals per second. The average fatigue crack growth life under turbine standard spectrum loads observed was observed to be lower in GTM718 when compared to GTM 720 material. The measured crack growth life was about 48 blocks and 38 blocks in GTM 720 and GTM 718 respectively. It was clear from these experiments that GTM720 is more damage tolerant than GTM718 material.

A large number of researches and studies have been carried out since ancient times to enhance the performance of concrete to make concrete environment friendly. Fiber-reinforced concrete (FRC) is one of those advances which offers a convenient, practical, and cost-effective method to overcome micro-cracks and similar deficiencies. In this research, the authors attempted to use naturally available chopped human hair (HH) as fibers in concrete to enhance the performance of concrete. Human hair is non-biodegradable material existence in nature. The study aims to find the optimum dosage of HH as a fiber in concrete in varying percentages like 0%, 0.5%, 1%, 1.5%, 2%, & 3% by weight of cement in concrete. Authors investigated the effect of concrete properties like fresh, hardened, and durable properties using HH in varying percentages. This investigation's experimental outcomes indicate that using HH as a fiber enhances the better bonding between ingredients of concrete by exhibiting enhancement in properties of up to 2.5% dosage as fiber. Overall, the study reveals that 2–2.5% is the optimum use of HH as a fiber in concrete. The use of HH as a fiber enhances concrete performance and reduces the cost of concrete and disposal challenges.

Industrialization is blossoming gradually and has uplifted the living standard of human beings. Now it became hazardous to environment, because of disposal challenges due to waste by-products. Manufacturing of copper-based products consumes natural resources, energy, it emits various greenhouse gasses to the environment and causes natural depletion. Whereas, construction industry consumes natural resources like, river sand, aggregate, wood, lime and clay to manufacture cement to name a few on a wide scale to build infrastructure. In this research, to reduce the resource consumption, to overcome the environmental challenges due to waste by-products, authors used waste copper slag. Authors attempted use of waste copper slag (WCS) as a substitute for river sand in M40 grade concrete. Similarly, poly propylene fibres (PPF) are used to study the effect of fibres on concrete prepared with WCS. This research concentrates on mechanical and fresh properties of concrete prepared with and without PPF on use of WCS as a partial replacement of river sand. Experimental findings indicate that, use of WCS improves the fresh properties of concrete linearly. Also, mechanical properties of concrete prepared with up to 60% WCS by weight of sand enhances strengths of concrete in marginal rate. Use of WCS as a substitute for river sand, helps in reducing the cost of concrete preparation and consumption of natural resources. This research helps researchers and practitioners in making concrete sustainable and eco-friendly by using WCS.

Preparation of subgrade plays an significant role in construction of roads as it acts as the foundation to the flexible pavement. The soil subgrade can be utilized to its full extent only if it is well compacted, the subgrade strength is related to the CBR of soil. Determination of stiffness modulus and shear strength of the subgrade using California bearing ratio (CBR) test. The CBR values be contingent on the nature & other properties of soil. CBR test is very laborious, time overwhelming & always be performed on moulded soil samples which makes it difficult to get accurate values and also to implement in reality. In the present study the authors have made an attempt to calculate the CBR values and the index properties of the soil and to develop a relationship between them so that one can obtain reliable CBR values in less time. The authors have collected the samples from Chickballapur district, India and correlated unsoaked and soaked CBR value with maximum dry density, optimum moisture content, percentage fines, liquid limit and unconfined compressive strength etc. Experimental outcomes indicates that the soil properties influence the CBR value of soil. Correlations are developed between the California bearing ratio and maximum dry density with satisfactory R2 values with which CBR values can be predicted.

This research reports the experimental investigation, capturing the effect of engineered fibers on fresh and mechanical properties of M50 grade concrete blended with poly-vinyl chloride (PVC) waste powder with one mineral admixture and one chemical admixture as superplasticizer. In this experimental investigation fourteen mixes (seven mixes with fibers and seven mixes without fibers) are prepared using ground granulated blast furnace slag (GGBS) as mineral admixture and PVC waste powder. In these mixes PVC waste powder content is varied in 0% (treated as reference mix), 5%, 10%, 15%, 20%, 25% and 30% by weight of cement whereas, 30% of GGBS is kept constant except reference mix. 0.6% of sulpho-naphthalene formaldehyde (SNF) as superplasticizer, by weight of cement are kept constant in all the mixes. Similarly, to study the effect of fibers on fresh and mechanical properties of concrete, 0.5% of engineered fibers are used along with 0.6% of superplasticizer. So that a comparison between with and without fibers could be prepared. Fresh properties of concrete are studied by using slump and compaction factor test for all the mixes. Similarly, the prepared test specimens are tested for the mechanical properties like compressive, flexural and split tensile strength as per Indian standard IS:516-1959 at 7, 14, 28and 90-days curing period. Test results indicates that up to 20% PVC waste powder can be used as a partial replacement of cement along with 30% GGBS, 0.6% of SNF superplasticizer, and 0.5% fibers in M50 grade concrete without compromising strength properties. Use of engineered fibers along with GGBS and PVC waste powder not only helps in reducing the cement consumption, but also improves strength properties and facilitates in lowering the cost of construction.

Natural fibers have grown extensively during the last few years and have become interesting to scientists and researchers as an alternative preference for wood dust fiber composites. As they have good mechanical properties, cost adequacy, non-abrasiveness, high particular quality, eco-accommodating, and biodegradability features. They are abused as a trade for traditional fibers like carbon and glass. In present correspondence, the study on the preparation and characterization of a new arrangement of green composites, including Tectona Grandis wood flour fiber as a strengthening material in polymer grid based on epoxy resin has been accounted. The stable mechanical properties of erratically orientated personally blended Tectona Grandis wood flour fiber-reinforced polymer green composites such as tensile, compression, and hardness properties were explored as a purpose of fiber loading. The reinforcement of resin with Tectona Grandis wood dust fiber is accomplished in particulate fiber by employing optimized resin. These fibers were blended with epoxy resin in diverse fortification strengthening percentages. The outcome of the above said mechanical properties were measured. It has demonstrated a development in these stable mechanical properties after reinforcement by fibers. The estimation of static mechanical properties will increment in an increasing percentage of reinforcement. The average ultimate tensile strength is 17.50 MPa, and the compression strength is 246.93 MPa. The microstructural behavior of these composites is studied with the help of scanning electron microscopy (SEM), and the moisture absorption test is also carried out.

Many researchers have carried out works on use of various agricultural and industrial by-products to enrich the performance and strength characteristics of concrete. The study here reports and captures the use of coconut shell (CS) as partial replacement to coarse aggregate (CA). CS is a naturally available abundant agricultural waste material, which can be used as an alternate to CA. For this research, authors considered M20 grade concrete to investigate the rheological and strength characteristics of concrete incorporating CS as an alternate material for CA in varying percentages like 0%, 5%, 10%, 15%, 20%, 25%, and 30%. The study aims to find the optimum dosage of coconut shell that can be replaced partially in concrete to enhance the strength characteristics and to make concrete lightweight by overcoming the disposal challenges of agricultural waste. Total of seven mixes are considered for this investigation to attempt CS a substitute for CA. The rheological properties like slump & compaction factor tests are conducted for fresh properties. Similarly, strength characteristics of concrete like compressive, split tensile and flexural strength tests are performed to measure the structural performance of CS as a CA. Test outcomes of this investigation exhibits that, CS can be replaced up to 20% by weight of CA, without compromising the strength characteristics and rheological properties of concrete. Use of CS as a CA in concrete production not only contributes to performance and strength of concrete but also solves the solid waste disposal problem and helps in conserving natural resources.

The purpose of this review article is to effective utilization of alccofine as a supplementary cementitious material (SCM) in concrete. Concrete is the most extensively used man-made construction materials in the ecosphere. Cement is the binder material for producing the concrete. During the clinkering process in cement industry, large amount of CO2 is produced as a byproduct and emits into the atmosphere. This CO2 dominates the major share of total greenhouse gases (GHG) released in to the atmosphere. Hence to reduce GHG emission, research activities have been transforming from conventional materials to other supplementary materials. To support the recent research evident researchers are using, fly ash, GGBS, Rice husk ash (RHA), silica fume, Phosphogypsum, Metakaolin, etc. are widely used as a SCM in concrete due to pozzolanic reactivity. One among the SCM, alccofine (1203), is a recent trend microfine material that can be used in concrete as a partial replacement material for cement. This review paper presents a summary of the published literature by several researchers who have intended to highlight the importance of alccofine as a SCM in the various fields of the concrete industry. In this review article authors exhibiting a detailed review on utilization of alccofine as a SCM to improve the fresh, mechanical & durability properties of concrete. Each byproduct has a varying mineral content. Alternatively, there is huge problem for the disposal of the byproducts. They appraised the alccofine, when partly replaced with cement, showed a remarkable improvement in both mechanical as well as durability properties at all ages. But the micro structure and fire resistance properties were not yet approached by the current research, hence this gap is addressed as a future course of research.

The Construction industry consumes a large amount of natural resources and energy. It is one of the main sources of waste generation and greenhouse gas emissions (GHG). The preparation and utilization of concrete have a great impact on climate change and environmental pollution. Environmental impact assessment of concrete is of prodigious importance in terms of accomplishing a sustainable society. Cement is a commonly used binding material for the preparation of concrete. The manufacture and utilization of cement in concrete are main responsible for GHG emission and climate change. In this research, to measure the environmental impact of concrete, the Life cycle assessment (LCA) model is prepared by using SimaPro 9.1 software and Ecoinvent database. Concrete is prepared with three different categories of binding materials like Portland cement (OPC), ground granulated blast furnace slag (GGBS) and portland pozzolana cement (PPC). Results indicate that, PPC and GGBS have greater impact on environment when compared to OPC.