Workability and durability analysis of waste based geopolymer concrete

GPC as a promising material, started gaining momentous attention from the researchers and construction specialists because of its advantages in using by-products from agriculture and industries to replace cement thereby reducing greenhouse gas emission. Workability and durability tests were carried out, so as ascertain the efficiency of the rice husk ash and rice husk as sodium silicate and super plasticizer, for solving efflorescence problem known with geopolymer concrete.  The factory-made sodium silicate was also used and compared with laboratory-produced, before addition of other geopolymer binders such as kaolin clay and fly ash. Brunauer-Emmett-Teller (BET) scrutiny that delivers quantitative data on the specific surface area as well as porosity dispersal of solid materials revealed that correlation coefficient of RHA (0.994) was higher than that of cement (0.991).  Besides, RHA has higher surface area (250.023 m3/g) than the cement utilized which stood at 211.49 m3/g. Though the c constant of cement exceeds the RHA values, RHA can serve as good pozzolanic material and cement substitute. It is seen that the workability of laboratory-produced sodium silicate and superplasticizer geopolymer concrete was enhanced significantly compared to that of prior geopolymer systems. It is observed that the workability of the geopolymer concrete was considerably enhanced compared to that of orthodox geopolymeric systems, especially at 2.5% rice-husk created superplasticizer and higher content of laboratory-produced sodium silicate

Indonesia MICE green building project with value engineering and its influential factors: an SEM-PLS approach

The MICE industry is considered one with high economic attractiveness for investors. Regulations and user requests for a new building are required to meet green building standards. The Green Building Council Indonesia issues Greenship's green building certification system. A minimum of 56 points is required for additional investment costs but will result in savings in operations to get a platinum rating. This paper aims to determine what factors are influential in optimising construction costs through the value engineering method to achieve a green building rating tool with life cycle costs using Structural Equation Modelling. The finding is that energy is the most influential factor in obtaining platinum rating certification, which requires value engineering and lifecycle cost analysis to achieve optimal investment costs with additional costs from 7,494% to 4,689%. The novelty of this research is that the selection of materials/machines and working methods of the green concept that saves energy needs to be carried out from the beginning of the design to achieve a feasible payback period for new investments, which will be the commitment of the owner to build a green MICE.

Fabrication of mercury (Hg) sensor based on Tire Waste (TW) carbon electrode and voltammetry technique

Voltammetry is widely used to detect heavy metals such as mercury (Hg). The sensor material influences the results of the voltammetry method. Carbon-based sensors are commonly developed because of their wide potential range, low background current, inexpensive, inert, and suitable for various sensors. Recently, Tire Waste (TW) was chosen as a carbon source for the manufacture of electrodes because it is rich in carbon (88%). The material is easy to obtain, green technology and a carbon source that has not been properly utilized. Separation of carbon material from TW using the pyrolysis method produces 4.32 gr (2.6%) of soot (from 200 gr TW) as a material for making carbon-based Hg sensors. The XRD pattern of TW soot has amorphous phases. SEM topography shows that the surface of TW soot consists of particles that are almost uniform in shape. The estimated particle size is about 0.25 µm. The sensor was made with a mixture of TW soot and paraffin with a 2:1 ratio. Testing the specific value of sensor capacitance using the Cyclic Voltammetry (CV) method showed the presence of cathodic and anodic currents. The Hg deposit occurred at a peak cathodic current at a scan rate of 20 mV/s. The Limit of Detection (LoD) value is 0.0681 ppm and the Limit of Quantitation (LoQ) is 0.229 ppm. Measurement of Hg in natural water samples used river water from the Aceh Jaya sub-district at two points representing the upstream and downstream of the river. The Hg concentrations obtained were 0.000536 ppm and 0.00182 ppm, respectively and were compared with the inspection results using Atomic Absorbance Spectroscopy (AAS), 0.00058 ppm and 0.00186 ppm, respectively. The t-test results of the two Hg measurement methods at a significance level (α) of 5% obtained tcount > ttable (0.0208 <2.306), indicating that there is a significant difference between the two Hg concentration measurement methods for natural water

Key success factors analysis for improving cost performance of green retrofit infrastructure on the jetty project

Several rating definitions must be met following the envision's system. The envisioned system aims to develop the green building concept in the existing jetty building. These definitions are quality of life, leadership, resource allocation, nature, climate, and resilience. This sustainability is needed to initiate changes in the planning, design, and provision of sustainable infrastructure together with the company. This also applies to implementing long-term infrastructure investments that are more cost-effective, resource-efficient, and adaptable. The study uses a qualitative and quantitative method, where data is obtained by distributing questionnaires and simulating using Statistical Products and Solution Services (SPSS). The application of Value Engineering (VE) and Life Cycle Cost Analysis (LCCA) has been chosen by researchers on existing jetty buildings with the green jetty concept, with investment costs in economic green jetty buildings and a return on investment costs of less than four years. In achieving the ten most influential factors in improving cost performance in sustainable dock construction, the results of the SPSS simulation processing obtained the ten most influential factors, namely: Planning, Energy, Siting, Materials, Ecology, Community, Economy, Operation, and Maintenance Cost, Follow-up Inspection, and Labor Experience

A review towards Friction Stir Welding technique: working principle and process parameters

Friction Stir Welding (FSW) is a solid-state bonding process that employes tools that are not used up and can function to connect two opposite workpieces without melting the workpiece material. The friction force has been micro-structurally tested to reformat or transform the inner state of the structure properties (atomic formation) form in metal since the kinetic energy of friction has been utilised in one of the welding techniques. Right afterwards, the studies reported that the mechanical properties also underwent a significant deformation. The aim is to determine the effect of Welding Procedure Specification (WPS) product quality. As it develops through research and applied experiments, the branch of friction-based welding discipline can be classified depending on how the friction mechanism can produce the finest solid-state joint, which is suitable to the typical property of metal and can be maximised by joint configuration. Friction Stir Welding is a friction-based welding technique that uses the stirring tool to generate friction while the workpieces are stuck on the line of the FSW joint configuration. The relevant correlations amongst process parameters and inside its respective adjustable variables are constructed to the finest principles that produced top-grades empirical reports of the weld properties. In this review, the explanation of the working principle and clarification of process parameters are presented. The cited references are selected from creditable and verifiable articles and books in the last ten years. Expectedly, it will be able to pioneer a new face of simple and understandable review articles

Design of supply chain risk mitigation system using house of risk and Fuzzy AHP methods in precast concrete

Today's global supply chain has many risk factors. These risks include supply disruptions, supply delays, demand fluctuations, price fluctuations, and exchange rate fluctuations. Risks that arise and cannot be mitigated properly in the supply chain can disrupt the company's business processes in various sectors. Companies in the construction sector when working on construction projects face many risks during the project cycle, especially risks in the supply chain process. Partial risk management, namely only on construction projects and not specifically on the supply chain process, causes potential risks in the supply chain process not to be identified in detail, and mitigation strategies cannot be determined effectively for risks in the supply chain. This research was conducted to identify risks and determine appropriate mitigation strategies using the house of risk as a framework and a fuzzy analytical hierarchy process weighting method to select the best mitigation strategy. The research results showed that there were 26 risk events and 21 risk agents identified, and the 5 best mitigation strategies were chosen from the 10 formulated strategies for a mitigation monitoring system. Based on research results, the best risk mitigation strategy can be used as a reference for risk mitigation actions in the company's supply chain as outlined in the form of a dashboard monitoring system

Quality system as a mediating variable of the relationship between lean manufacturing and operational performance in the food industry

The failure to implement lean manufacturing (LM) in the food industry was caused by the overlapping application of LM tools. The application of LM in the food industry is experiencing problems in the form of confusion in the placement of QS or Quality Control (QC). This problem is the background of this research. The objective of this study is to compare two methods of the implementation of LM in improving operational performance (OP), namely (1) making quality control (QC) a part of LM practice and (2) making quality control (QC) a part of the quality system (QS). The applied analytical method was the Structural Equation Modelling (SEM) based on Partial Least Square (PLS). The research findings indicated that "making QC a part of QS" can optimally mediate increasing LM against OP. This study's originality is a comparison of the relationship between LM and OP based on the two methods with large sample sizes. The implications of the findings are expected to become recommendations for applying LM in the food industry, especially in terms of placing quality in its implementation