DEVELOPMENT AND MECHANICAL BEHAVIOUR OF SELF-COMPACTING GEOPOLYMER CONCRETE

High consumption of natural resources, environmental concern of CO2 emission due to cement production and improvement on concrete performance has become a driving force behind the search for alternative materials. An effort made in this regard is the development of self-compacting geopolymer concrete (SCGC). SCGC is a novel material that involves innovation in the production and casting of concrete. It is a type of concrete that does not require compaction for placing it and can be produced by completely eliminating ordinary Portland cement. So far several studies have been done on the characteristics of self-compacting concrete and that of geopolymer concrete in both fresh and hardened state. However, no work has been conducted on SCGC

DEVELOPMENT AND MECHANICAL BEHAVIOUR OF SELF-COMPACTING GEOPOLYMER CONCRETE

High consumption of natural resources, environmental concern of CO2 emission due to cement production and improvement on concrete performance has become a driving force behind the search for alternative materials. An effort made in this regard is the development of self-compacting geopolymer concrete (SCGC). SCGC is a novel material that involves innovation in the production and casting of concrete. It is a type of concrete that does not require compaction for placing it and can be produced by completely eliminating ordinary Portland cement. So far several studies have been done on the characteristics of self-compacting concrete and that of geopolymer concrete in both fresh and hardened state. However, no work has been conducted on SCGC

EFFECT OF SODIUM HYDROXIDE CONCENTRATION ON FRESH PROPERTIES AND COMPRESSIVE STRENGTH OF SELF-COMPACTING GEOPOLYMER CONCRETE

This paper reports the results of the laboratory tests conducted to investigate the effect of sodium hydroxide concentration on the fresh properties and compressive strength of self-compacting geopolymer concrete (SCGC). The experiments were conducted by varying the concentration of sodium hydroxide from 8 M to 14 M. Test methods such as Slump flow, V-Funnel, L-box and J-Ring were used to assess the workability characteristics of SCGC. The test specimens were cured at 70°C for a period of 48 hours and then kept in room temperature until the day of testing. Compressive strength test was carried out at the ages of 1, 3, 7 and 28 days. Test results indicate that concentration variation of sodium hydroxide had least effect on the fresh properties of SCGC. With the increase in sodium hydroxide concentration, the workability of fresh concrete was slightly reduced; however, the corresponding compressive strength was increased. Concrete samples with sodium hydroxide concentration of 12 M produced maximum compressive strength

A Review on Potential use of Coal Bottom Ash as a Supplementary Cementing Material in Sustainable Concrete Construction

The demand of concrete is increased rapidly due to worldwide growth in infrastructural development. Consequently, consumption of concrete also raises the demand for Portland cement, because it is the fundamental material in concrete construction. The increasing demand for Portland cement is expected to be encountered by introducing new supplementary cementing materials. Considering the sustainability of construction, it is imperative to develop supplementary cementing materials from the industrial waste by-products; one of such waste is the coal bottom ash, produced by coal-based thermal power plants. Previously several studies have been conducted on the utilization of coal bottom ash in its original form as natural sand replacement but limited research has been reported on the coal bottom ash as replacement of cement. It was observed through the literature review that the original coal bottom ash is porous in nature, and cannot be used as a replacement of cement, but after the proper grinding, it possesses the good pozzolanic property and could be utilized as replacement of cement in concrete. The result of this review has indicated that ground coal bottom ash has a good potential to be utilized as supplementary cementing materials in concrete construction. The aim of this review is to summarize the previous findings on the utilization of coal bottom ash as supplementary cementing materials in concrete construction. Hence, this article will deliver the key information and valuable material for the researchers looking for the supplementary cementing materials in the field of advanced concrete technology

Precision Agriculture using Internet of thing with Artificial intelligence: A Systematic Literature Review

Machine learning with its high precision algorithms, Precision agriculture (PA) is a new emerging concept nowadays. Many researchers have worked on the quality and quantity of PA by using sensors, networking, machine learning (ML) techniques, and big data. However, there has been no attempt to work on trends of artificial intelligence (AI) techniques, dataset and crop type on precision agriculture using internet of things (IoT). This research aims to systematically analyze the domains of AI techniques and datasets that have been used in IoT based prediction in the area of PA. A systematic literature review is performed on AI based techniques and datasets for crop management, weather, irrigation, plant, soil and pest prediction. We took the papers on precision agriculture published in the last six years (2013-2019). We considered 42 primary studies related to the research objectives. After critical analysis of the studies, we found that crop management; soil and temperature areas of PA have been commonly used with the help of IoT devices and AI techniques. Moreover, different artificial intelligence techniques like ANN, CNN, SVM, Decision Tree, RF, etc. have been utilized in different fields of Precision agriculture. Image processing with supervised and unsupervised learning practice for prediction and monitoring the PA are also used. In addition, most of the studies are forfaiting sensory dataset to measure different properties of soil, weather, irrigation and crop. To this end, at the end, we provide future directions for researchers and guidelines for practitioners based on the findings of this revie

Study of Compressive Strength of Concrete with Coal Power Plant Fly Ash as Partial Replacement of Cement and Fine Aggregate

This research study comprises of concrete cubes made with Ordinary Portland Cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25%, 50%, 75% and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10%, 25%, 50%, and 75% of cement with fly ash. The cubes were 6\" x 6\" in cross-section, and the mix design was aimed for 5000 psi. After proper curing of all 81 cubes, they were tested at 3, 7 and 28 days curing age. The cubes were tested in Forney Universal Testing Machine. By analyzing the test results of all the concrete cubes, the following main findings have been drawn. The compressive strength of concrete cubes made by replacing 100 % fine aggregate by fly ash was higher than the concrete cubes made with Ordinary Portland Cement at all 3, 7 and 28 days curing ages. On the other hand, the compressive strength of concrete cubes made by replacing 10 % and 25 % cement by fly ash was slightly lower than the concrete cubes made with Ordinary Portland Cement at all curing ages, whereas, the compressive strength of concrete cubes made by replacing 50 % and 75 % of cement by fly ash were quite lower than the concrete cubes made with Ordinary Portland Cement at all curing ages

Prefabrication in Building Construction: A Perspective of Pakistan Construction Industry

Construction industry is facing many problems in terms of construction waste, quality, environment, durability, safety and higher construction cost. Adoption of prefabrication is a possible solution to such problems. Accordingly, there is a need to study the prospects that would stimulate the appropriate discussion of the suitability of prefabrication and other construction methods for concrete buildings. Therefore, this study investigates the significance of advantages in adopting prefabrication along with hindrances through questionnaire survey. The data has been analyzed using RIW (Relative Importance Weight) method as a MCDM approach. The results depict that main advantages of prefabrication are ?Shorter construction time? and ?Less construction site waste?. The top hindrances in adopting prefabrication as identified in this study are: ?Higher initial construction cost? and ?Inflexible for design changes?. Based on the survey results and apparent progress in the adoption of prefabrication around the world, it is concluded that the use of prefabrication is likely to increase in developing countries like Pakista

Factors Contributing to the Waste Generation in Building Projects of Pakistan

Generation of construction waste is a worldwide issue that concerns not only governments but also the building actors involved in construction industry. For developing countries like Pakistan, rising levels of waste generation, due to the rapid growth of towns and cities have become critical issue. Therefore this study is aimed to detect the factors, which are the main causes of construction waste generation. Questionnaire survey has been conducted to achieve this task and RIW (Relative Importance Weight) method has been used to analyze the results of this study. The important factors contributing to the generation of construction as identified in this study are: frequent changes/ revision in design during construction process; poor scheduling; unavailability of storage; poor workmanship; poor layout; inefficient planning and scheduling of resources and lack of coordination among supervision staff deployed at site. Based on the identified factors, the study also has presented some suggestions for the reduction of construction waste in building construction projects of Pakistan