Journal of Building Materials and Structures

Geopolymer Cement: an Initiative towards the Replacement of Grey Cement by Green Cement in Future

2021-02-05T21:43:04+00:00

The emissions of greenhouse gases such as carbon dioxide from the production of Ordinary Portland Cement and Blended Portland Cement have widely affected the environment with increase in infrastructure development worldwide. Secondly, due to the continuous mining of limestone for the production of cement there is also simultaneous depletion of natural resources and hardly will it last up to maximum 40 years. Hence we need to switch over to some other alternate binders for constructions purpose in future. Geopolymer Cement is one of the inventions which is produced by a polymeric chain reaction of alkali-activated alumino-silicate materials better known as alkali activator (NaOH/Na2SiO3) binders with the industrial by-product materials such as Fly Ash, Rice Husk Ash, Slag, Crusher Dust etc. and provides high compressive strength which is comparable to BPC and reduces the carbon foot print. The objective of our study is to prepare the low CO2 foot print green Geopolymer Cement which may substitute the Ordinary Portland Cement and Blended Portland Cement in future and will helpful to reduce the greenhouse effect up to some extent and takes an initiative towards the green revolution movement.

A case study of foundation failure of a residential building: From diagnosis to reparation

2021-02-02T17:13:31+00:00

The pathology that appears in reinforced concrete structures, old and new, is inevitable and involves all stakeholders at all levels of responsibility, from the technician to the decision maker at the highest level. It also concerns engineers from design offices and experts from offices responsible for diagnosing existing structures, as well as engineers from repair companies. Like all countries in the world, the study of the pathology and safety of civil engineering buildings is one of the big problems encountered in the field of construction in Algeria. The foundations are among of the structural elements of the buildings most affected by this damage, these constitute the link between the structure and the soil, they allow the transmission of loads from the structure to the soil. If these structural elements are damaged, they affect the general stability of the building. Depending on the severity of the damage, it can cause the building collapse. The main objective of this paper is to study a pathological case of foundation failure of a residential building: from diagnosis to reparation. This repair was carried out according to an intervention plan comprising stages spread over time, this allowed the strengthening of the infrastructure and gave the building an acceptable level of security.

Exploration of prefabricated building system in housing construction

2021-02-27T17:24:14+00:00

The main purpose of this paper is to examine the development and current status of prefabrication techniques and their application in building construction and why its use is still limited in the housing sector in India and why prefabrication is not being used so far to provide affordable housing to all. Prefabrication is the practice of assembling components of a structure in factories, and then transporting the complete assemblies or sub-assemblies to the construction site where the structure is to be located. The important aspect is how much of a potential difference it can establish so that appropriate development can be implemented. This paper reviews the current prefabrication system scenario for housing in India. The paper begins with a brief introduction about different types of prefabrication system. Subsequent topics address the need of prefabrication and ethical dilemma of technology transfer for prefabricated building system in India. In this paper, a qualitative descriptive evaluation research method has been used. The research methodology comprises of case studies, visual observation and data collection. Finally, two case studies around the world have been presented to validate and illustrate the various modern trends and application of design and construction methods of prefabricated building system in housing.

Study of the mechanical behavior of dune sand treated by hydraulic binders: application in the road geotechnical field

2021-03-22T17:34:03+00:00

The purpose of this work consists of valorizing a local sand dune which is found in abundance in the region of Djelfa (Algeria); for use in pavement foundations. For this investigation a method of formulation has been proposed, which based on the stabilization of this material using a mixture of two hydraulic binders. Various mixtures were subjected to classification tests, tests grain size distributions, tests of compaction with modified Proctor, shear strength, tests of bearing pressure (CBR unsoaked and soaked), compressive strength and tensile strength. The results obtained have shown that some mixtures are of high mechanical characteristics and could be then used in road foundations.

Numerical investigation to reduce environmental emissions from manufacturing industries

2021-03-22T17:34:02+00:00

This paper aims to study carbon dioxide emissions from the cement manufacturing under wind conditions. These effects are investigated by Computational Fluid Dynamics (CFD) code used both method such as a Large Eddy Simulation (LES) and K-ε methods to investigate a spread of pollution in vicinity of manufacturing. The predicted concentration, velocity and temperature of CO₂ were used as the safety criterion to provide the useful information about a pollution amount resulted under variant environmental and structural conditions. A detailed look at results is beyond the scope of analysis to determine optimal CO₂ emission. From the present numerical simulation the carbon dioxide appears to be the best candidate as tracer gas and Simulation (LES) methods, which directly calculate the large-scale turbulent structures and reserve modeling offer the best analysis of turbulent flows.

ANN modelling approach for predicting SCC properties - Research considering Algerian experience .Part II. Effects of aggregates types and contents

2021-06-30T11:11:19+00:00

The objective of this investigation is to illustrate the effect of aggregates types and contents on fresh and hardened properties of self-compacting concrete (SCC) considering Algerian experience. Based on experimental data available in the literature, Artificial neural network (ANN) models are established to illustrate the variation of aggregate types and contents (sand and gravel) in binary and ternary contour plots. Modelling results concerning the effect of sand types and proportions in binary and ternary combinations show the beneficial effect of river sand (RS) and crushed sand (CS) on slump flow. The highest L-Box ratio was obtained for mixtures composed of 50% of both RS and CS for binary and ternary mixtures. The increase in CS content enhance static stability, while the increase in RS gives higher compressive strength at 28 days. Concerning the study of aggregate sizes and contents, it was found that the increase of sand content leads to an increase in flowability and a decrease in static stability. An increase in gravel content leads to a decrease in passing ability, while a significant improvement in viscosity, static stability and mechanical strength with an increase in gravel content were observed.

A case study on deterioration assessment and rehabilitation of fire damaged reinforced concrete structure

2021-07-01T15:33:52+00:00

Fire is one of the most severe hazards that building structures may experience during their lifetime. A fire spread to the whole structure can cause unexpected damages to the structural elements. Mainly, the building type is crucially important for the type and the level of damage to the building because of the fire. Post fire investigation of damaged structure is required to determine the extent of damage to concrete elements and to work out system of effective repair/rehabilitation measures to maintain the structural integrity of fire effected structural components. The paper covers in brief the strength and durability study on fire damaged building in Delhi, India. The study reports the extent of fire damage. Optical Microscopy (OM), X-Ray Diffraction (XRD) and Deferential Thermal Analysis (DTA) studies were carried out on the sample concrete cores extracted from different identified portions of the fire exposed concrete are highlighted in this paper. Extent of damage occurred in the Reinforced Cement Concrete (RCC) i.e. RCC columns/beams/slabs are described based on the detailed evaluation by various Non-Destructive Evaluation Techniques covering Cover study & Ultrasonic Pulse Velocity (UPV) testing. Repair and remedial measures required for restoration and strengthening of the fire affected RCC columns/beams/slabs using indigenously available repair materials and techniques are also highlighted in this paper.

Use of bottom ash as part replacement of sand for making concrete blocks

2021-07-06T15:35:33+00:00

Coal-based thermal power plants all over the world facing serious problems of handling and disposal of the ash produced. The productive use of coal Bottom Ash (BA) is the best way to alleviate the problems associated with its disposal. This paper covers the studies on laboratory scale evaluation of vibro compaction concrete blocks using BA I, BA II & BA III collected from three different location of Coal Fed Thermal Power Station. In the present investigation laboratory investigation have been carried to utilize BA as part replacement of sand in concrete. This study cover manufacture of concrete blocks without flyash & with BA using for making solid block as per specification laid down in IS:2185 using vibro compaction machine. Three different sources of BA were used in concrete mix each @ 30%, 40% & 50% replacement by weight of sand were adopted in making concrete blocks. Comparative study of compressive strength of concrete at different age of curing, wet density, drying shrinkage is reported in this study. Wet density is found to be lower in blocks containing BA & dry shrinkage values are found well within the limits of specifications. Concrete Blocks having BA @ 30% by weight of sand are found suitable for use in the manufacture of concrete blocks.