Proposed Structural Reliability-Based Approach for the Classification of Concrete Quality

Implementing just‐in‐time (JIT) management in the ready mixed concrete (RMC) industry seems viable. It has been observed previously by others that the current practices for managing the concrete supply chain upstream in terms of raw materials acquisition or prerequisite work on site were not geared toward JIT production. However, it is unclear if this observation is also relevant for the procurement of raw materials in the RMC industry in Chongqing (in China) and Singapore. Hence, the purpose of this study is to investigate the implementation status of JIT in the RMC industry in Chongqing and Singapore. The field study conducted found that all the RMC suppliers surveyed were using the demand pull system to manage RMC production and delivery to sites. However, the study also found that the raw materials could be purchased either using the JIT purchasing method or the traditional economic order quantity (EOQ) purchasing method. Further studies to investigate the conditions where a RMC supplier can adopt the JIT purchasing method to procure its raw materials are recommended.

RETRACTED: The impact of GGBS and ferrous on the flow of electrical current and compressive strength of concrete

Concrete quality issues in multistory building construction in Ghana: Cases from Kumasi metropolis

In the world of construction, concrete quality plays a very important role because it directly affects the strength and durability of building structures. The purpose of this research is to appraise and evaluate the efficiency of using the T² Hotelling control chart method in controlling concrete quality at PT. Wijaya Karya Beton Tbk by analyzing three main concrete quality parameters: slump, compressive strength, and tensile strength, based on data collected from January to February 2025. The methods employed include multivariate analysis approaches, such as correlation tests, multivariate normality tests, Johnson transformation to improve non-normally distributed data, and the application of generalized variance control charts and T² Hotelling control charts. The results of the study indicate a significant correlation between concrete quality variables; however, the initial data did not meet the assumption of multivariate normality, necessitating the Johnson transformation, which proved effective in improving data distribution and enabling the application of Hotelling's T² analysis. Based on the control charts, most observations remained inside the established control limits; however, some samples fell outside the boundaries, indicating process disturbances. Overall, this study concluded that the Hotelling T² method is effective in detecting process nonconformities at an early stage, thereby serving as a foundation for continuous improvement in concrete production quality and making a significant contribution to strengthening the quality control system in the national construction sector.

Concrete as the main construction material has an important role in determining the strength and reliability of a construction project. The quality of concrete is influenced by the properties of its constituent materials, such as gravel, sand, cement and water. Testing the compressive strength of concrete is an important step to assess its quality and ensure it meets construction standards. Although previous research has compared the compressive strength of concrete and changes in aggregate volume, this research still covers limited dimensional variations and further exploration of aggregate dimensional variations is needed. This laboratory study used a conventional concrete design according to SNI 03-2834-2000, with compressive strength tests carried out at the Material Testing Laboratory, part of the Civil Engineering Department at Politeknik Negeri Banyuwangi Banyuwangi. The experimental results recorded in the fourth chapter show that at 7, 14, and 28 days, type AG 10 has the highest compressive resistance value, statistically significant mean value, and also shows that type AG 40 has the lowest compressive strength value. Therefore, it can be concluded that the smaller the size variation of coarse aggregate, the higher the compressive strength of concrete. These findings provide a comprehensive picture of the compressive strength characteristics of concrete with varying coarse aggregate sizes.

The key benefits from Ready Mix Concrete (RMC) are good quality, lower Life cycle cost, the speed of work and friendliness of environment more than the site mixed concrete, but when the quality of RMC is below threat of several causes resulting poor quality or useless concrete. We will lose all advantages of RMC that we mention before. Therefore, this study investigate the using of Quality management to improve the process of company to produc (RMC) in batching plant and study the impacts of Quality Control (QC), Quality Assurance (QA) on the company by introduce them to the process in order to make improvements on current Quality system to make it continuous improvements. The idea of the work depends on finding the relationship between the Project Management Body of Knowledge (PMBOK) Guide and the quality management by combining them together in process to achieve the best results as soon as possible, higher productivity, less rework, increased customers satisfaction, increased profitability and sustainability by finding company’s problems and achieving it through guidelines and instructions of PMBOK Guide also the principles, the tools and the techniques of Quality Management. In order to achieve that, we have investigated three main points: the first one is gathering information to identify the current quality system, the second is identifying and analyzing of these problems and the third is finding solutions based on the principles of management. With a view to manage the process of production, the author used many techniques and tools for management such as Flow Chart for a process, Ishikawa diagrams to define seven main group of problems, Check Sheet to the number of problems occurrence, the FMEA Analysis for thirty-five problems, 5 Whys Analysis to find sources of the problems, Solution effect Analysis to propose the possible solutions. The most important results from this study are the main reasons for the absence of management methodology in the company which is a defect in the Quality system (structure of company, procedure, and resources), lack of management experience and communication and lack interest of Total Quality Management in management methodology. The researcher found lacks in the thoughtful scientific methodology for the management in process of production, therefore the developing of the system of production in the RMC plant is to build a methodology based on a guide of Project Management Body of Knowledge 5th edition because of the maturity level of the project management knowledge areas.

Implementation of the use of hydration stabilizer admixtures at a ready-mix concrete plant

Concrete is a mixture of cement, fine aggregate, coarse aggregate, and water with or without additional ingredients to form a solid mass, its use is very common in building structures, but the final quality of the strength of the concrete depends on many factors, including the implementation of its manufacture. and immersion. The research aimed to determine changes in the quality of k-300 concrete and the maximum strength of concrete immersed in salt water. The research was carried out in the Laboratory of the Faculty of Engineering, University of 17 August 1945 Samarinda for 2 months. The stages of research activities are starting, literature study, preparation of materials and tools, testing concrete building materials in the laboratory, designing concrete mixes, making test objects/samples, evaluation, testing concrete compressive strength, conclusions, and reporting. Tests carried out in the laboratory include: (1) checking wear/abrasion of coarse aggregate using the Los Angeles method; (2) examination of coarse aggregate and fine aggregate sieve analysis; (3) examination of specific gravity and SSD absorption of coarse aggregate and fine aggregate; (4) checking water content; (5) checking mud and clay levels; (6) checking the bulk density of coarse aggregate, fine aggregate and mixed aggregate; (7) inspection of concrete slump experiments; (8) soaking concrete using seawater and freshwater; and (9) checking concrete compression strength. The research results show that: (1) The compressive strength of K-300 concrete soaked in seawater, namely 304,915 f'c, is lower than that soaked in fresh water, namely 308,580 f'c; and (2) differences in concrete compressive strength occur at old concrete ages (21 days and 28 days) but at young concrete ages (3, 7 and 14 days) there are no differences in compressive strength.

Concrete is a widely used construction material due to its high strength and durability. The quality of concrete is greatly influenced by the characteristics of the aggregates that make up 60–70% of the concrete volume. This study aims to analyze the effect of fine sand aggregate and coarse natural gravel aggregate from the Batanghari River on the compressive strength of concrete. Three sample variations were used, namely: AA (Mendapo Quarry and Kasang Quarry aggregates), BB (RBE Quarry and Sengeti Quarry aggregates), and AABB (a combination of AA + BB). The test specimens were cylindrical in shape, measuring 15×30 cm with a design quality of 20 MPa. Compressive strength testing was carried out at the ages of 7, 14, and 28 days according to SNI 1974:2011. The test results at 7 days of age were 5.436 MPa for AA samples, 5.067 MPa for BB samples, 5.879 MPa for AABB samples, at 14 days of age 16.080 MPa for AA samples, 13.389 MPa for BB samples, 14.829 MPa for AABB samples and at 28 days of age 20.907 MPa for AA samples, 17.403 MPa for BB samples and 22.036 MPa for AABB samples which produced the highest compressive strength. The combination of aggregates provides better gradation, low porosity, and higher density. The natural aggregates of Batanghari River are proven to be suitable for use in medium quality concrete.

Nowadays the use of concrete is increasing but the concrete raw materials fulfillment is decreasing. In this case, one of alternative is to be replacedthe coarse aggregate with lava stone waste obtained from the production residue of natural stone craftsmen in Sambirejo, Prambanan,Yogyakarta.The purpose of this research was to determine the concrete compressive strength, modulus of elasticity of concrete with lava stone wasteas substitute for coarse aggregate, and determine the maximum ratio of lava stone waste as the coarse aggregate in terms of compressive strength andmodulus of elasticity appropriate quality targeted.The method used in this research is the experimental method. Samples form is made as cylinder with 15 cm of diameter and 30 cm of high.Targeted quality of concrete is 25 MPa with lava stone percentage levels of 0%, 20%, 40%, 60%, 80%, 100% replaces the coarse aggregate.The compressive strength of concrete decreased at comparable levels with the addition of lava stone as the coarse aggregate. Value of the averagecompressive strength of concrete at 28 days was 36,768 MPa (lava stone 0%); 31,300 MPa (lava stone 20%); 28,283 MPa (lava stone 40%);27,152 MPa (lava stone 60%); 25,266 MPa (lava stone 80%); and 24,135 MPa (lava stone 100%). Modulus of elasticity was also decreasedlevels comparable to the addition of the lava stone. Average modulus of elasticity value is 22818,000 MPa (lava stone 0%), 18832,333 MPa(lava stone 20%), 16462,333 MPa (lava stone 40%), 15870,667 MPa (lava stone 60%), 15098,000 MPa (lava stone 80%), and13933,333 MPa (lava stone 100%). Concrete qualified targeted quality is lava stone concrete with the maximum level to 80% with averagecompressive strength is 25,266 MPa.

Deep learning based concrete compressive strength prediction model with hybrid meta-heuristic approach

In the design of new structures, EN 1992‐1‐1 normatively regulates the correlation between the compressive strength and tensile strength of concrete, in accordance with EN 206‐1. However, as there are many time‐ and load‐dependent impacts on existing structures, the relationship described by EN 1992‐1‐1 cannot be assumed without any further observations for existing structures. At the moment, there is no comprehensive investigation on the influences of, for example, subsequent hardening and carbonation on the concrete compressive or tensile strength. The tensile strength of concrete defined in EN 1992‐1‐1 is based on a water storage and a testing age of 28 days. Furthermore, the in‐situ tensile strength is affected by micro‐crack formation cause of internal stresses due to outflow of hydration heat, for example. Generally, there is a different influence of micro‐crack formation on the tensile strength of concrete than on the compressive strength of concrete. The actual value of the in‐situ tensile strength of concrete affects the shear force resistance and the load‐bearing capacity of anchors with concrete cone failure as decisive failure mode. Within the framework of a research project (SWD‐10.08.18.7‐13.01), financed by “Forschungsinitiative Zukunft Bau”, an initiative of the Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBR) structural investigations on the correlation between the compressive and tensile strength of old concretes have been performed. Below, the results of the research project are presented.

Quality control from raw material to finished ready-mix concrete is vital in the construction industry, where increasing demand aligns with industry growth projected at 4% annually. PT Bumi Sarana Beton (Kalla Beton) faces challenges in maintaining consistent quality due to variations in natural raw materials, which impact product quality and cost. This research investigates the company's quality control strategies, focusing on optimizing material selection and mix designs. Experimental research methods were used, including testing different mix proportions and assessing compressive strength and production costs. The study involved aggregate suitability testing, redesigning concrete mixes with fly ash, and evaluating cost-effectiveness. Findings show that using fly ash improves compressive strength and reduces costs. The research concludes that refined material selection and mix design strategies can enhance product quality and cost efficiency. Recommendations include further exploration of alternative materials, and rigorous quality control to sustain high production standards and maintain competitive advantage in the ready-mix concrete market

Circular economy in ready mixed concrete and construction industry is becoming popular all over the world and India is no exception to this.In this article the authors explore the use of ready-mix concrete industry waste when put back into concrete how the properties of concrete change and its effectiveness and suitability to ready-mix concrete industry.The authors also try to explore possibility of making a simple model for circular economy in ready-mix concrete industry especially with respect to use of ready-mix concrete waste.Ready-mix waste recycled aggregate (RWRA) obtained from the crushing of the ready-mix concrete waste can be used in the construction industry. Ready mix concrete waste is generated due to a result of poor workmanship, improperUtilising Ready-Mix Concrete Waste for Production of Sustainable Concrete and Creating Circular Economy

This study aims to evaluate the concrete quality of Pertashop buildings in Wonogiri Regency based on compressive strength results using the Concrete Hammer Test method (SNI 03-4430-1997). Building Approval or Persetujuan Bangunan Gedung (PBG) as well as Certification of Functionality (SLF) during the period from January to March 2024 with a total of 10 Pertashops in all areas of Wonogiri Regency with a test area of ​​9 test areas that were 28 days old. Each area was tested with 10 shots. The purpose of this study was to determine the quality results of the concrete structure quality of the Pertashop building in Wonogiri Regency based on the value of the hammer test compressive strength factor. From the results of concrete testing on the Pertashop building in Wonogiri Regency by taking samples of 10 points of the Pertashop location where it was built, it can be concluded that the Pertashop machine seat floor has a better concrete quality than K.225kg/cm2, while the Pertashop yard floor and Pertashop column pillars are still below the quality of K.225kg/cm2. Statistical tests in scatter-plots whose data comes from samples that are normally distributed multivariate, conclude that the quality of the Pertashop machine seat concrete plate H0 is rejected or data from two variables (Quality of floor slab concrete and column concrete).