Ready-mixed Concrete Research Articles

ANALISIS BEBAN KERJA DAN JUMLAH OPERATOR PENULANGAN RANGKA BETON UDIT

This study was conducted at a factory producing construction and building materials such as ready mix concrete, piles, udit concrete, and ryol. These products are produced in almost the same process, but on different production lines. There are 2 operators in the frame reinforcement section for udit concrete production. It is seen that the two operators have the same task but different results of their work, so that the production target is not achieved. The workload analysis method is used to determine the operator's actual load. Observation of activities is carried out by the work sampling method for 5 days. In work sampling, work and idle activities of workers are observed at randomly selected times and the amount of production during observations is recorded. From the study, it is known the ideal of actual load of each operator and the number of operators for the concrete frames reinforcement. The results showed workload of operator 1 was 95.11% while workload of operator 2 was 107%. The number of operators reinforcing concrete frames remains fixed for 2 people, but wage compensation needs to be given to operators 2 for excess workload refers to the amount of wages and provisions for overtime that are applicable in the company.

Waste generation from the production of ready-mixed concrete

In Brazil, ready-mixed concrete (RMC) suppliers are adopting management strategies to reduce waste generation. This is because of the increasing scarcity of adequate places for the deposition of waste, which raises the associated costs. Therefore, it is necessary to know the actual volume production of residues in order to optimize the implementation of the recycling. The waste produced in RMC plants are mainly in the form of leftover concrete and adhered to the internal part of the drum of the mixer truck.The present study analyzed the data and produced an inventory of the amount of waste generated by of one of the largest Brazilian concrete companies. In parallel, an experimental study was performed in the real conditions of an RMC plant in order to measure the influence of concrete characteristics on the volume of concrete adhered to the drum.The results showed that about 3% of all the produced volume returns to the plant, comprising approximately 1.6% adhered concrete and 1.4% leftover concrete. The study proved that the volume of concrete adhered concrete depends on the cement consumption and the slump. The volume of concrete loaded and the region where the RMC plant is located do not influence those results. The inventory showed that the main cause of concrete leftovers is associated to over order and corresponds to 58% of this volume.

Influence of type and composition of aggregate on mechanical parameters of concrete

The paper deals with a thorough analysis of the influence of the type of aggregate and its resulting grain size curve on the basic strength parameters of concrete. From the point of view of the type, natural crushed aggregate of amphibolitic type, natural crushed aggregate of granodioritic type and natural mined sedimentary aggregate of the psammitic type were monitored. The same concrete strength class was proposed for the analysis of the impact of individual types of aggregates. In one case it was a concrete mixture with a maximum aggregate grain size Dmax 16 mm with a continuous grain size curve and in the second case a concrete mixture with a maximum grain size Dmax of 22 mm with a discontinuous grain size curve, in the absence of a 4-8 mm fiction. In both cases, the mixture of individual aggregate fractions was determined so that the resulting grain size curve of the mixture was the same for all aggregate types. Thanks to this approach it was possible to directly monitor the influence of the type of aggregate and the grain size curves on the resulting concrete parameters. The results of the experiment show that a significant impact while maintaining the same grain size curves of the resulting aggregate mixture can be seen mainly in the type of aggregate. The absence of a 4-8 mm fraction when designing a concrete mixture with a Dmax of 22 mm proves to be completely problem-free from the point of view of concrete parameters in both fresh and hardened condition. A part of the research was also verification of the possibility of using natural crushed sand of fraction 0-4 mm for production of high-strength situ ready-mixed concretes.

A 3D Printed Ready-Mixed Concrete Power Distribution Substation: Materials and Construction Technology.

Currently, 3D concrete printing technology is not yet able to print ready-mixed concrete with coarse aggregates. Based on an independently developed 3D printing construction equipment system and optimized concrete materials, a 3D concrete printer that can directly print ready-mixed concrete is developed. This paper introduces the whole 3D printing process for one power distribution substation in detail, including the printing equipment, key software, concrete preparation, printing process, and construction inspection. This investigation will provide valuable design and construction experience for the future construction of 3D concrete printing.

Quality Management to continuous improvements in process of Ready Mix Concrete production

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.

Influence of stakeholder management and communications management in choosing of the best product achieve quality by Analytic Hierarchy Process method

This article investigate an analytical study of the stakeholder management and the communications management of Ready Mix Concrete, its importance and the role to identify, plan, management, engagement and control engagement in process of production to make decision about the best product achieve quality through the Analytic Hierarchy Process method (AHP) to compare criteria and variances pairwise comparison to choose best product meet with the requirements of quality management. The choice (best product) will determine the quality of actions that we can take without losses of costs for development of other products that can consume the time, effort and cost to correct or update its progress in the production process. Our choice of a product that reduces costs will help us to determine the tests and inspections that can achieve and have the most impact on quality (control and assurance). The Stakeholder management and communications management help us to determine criteria and variances as well as management. The author uses Expert Choice software for submitting goals, criteria, pairwise comparison of criteria and as well as submitting of alternatives. Moreover, the study of information base on the matrices of pairwise comparison to the alternatives with respect to cost, meet with standards, experience of functional manager, the reliability of engineering system, quality of human resources, safety and the analysis of the results based on sensitivity criterion, performance sensitivity, dimensional sensitivity, dynamic sensitivity, and the opinion of the experts, the best product achieve quality is Ready Mix Concrete more than other main products.

THE EFFECT OF AGE ON THE COMPRESSIVE STRENGTH OF CONCRETE BY USING ULTRASONIC PULSE VELOCITY

In this study, the effect of age on the strength development of concrete was investigated. For this purpose, specimens casted with ready mix concrete for different grades of concrete were obtained from ready-mix concrete firms available in Diyarbakir city which is the one of the biggest cities of Turkey. A few sets with different grade of concrete cube specimens were used in the experimental work. Each set included over 40 specimens. For measuring concrete strength development, two different tests were used: ultrasonic pulse velocity testing (UPV) and uniaxial compressive strength testing. After UPV and compressive strength tests, strength development for early ages was evaluated and defined. The aim of this work is to define the path of strength development of certain grades of concrete used in the east regions of Turkey. Another aim of the work is to be able to determine concrete strength through non-destructive UPV tests. As a result, it was seen that concrete strength development for early ages is not linearly proportional to age. Further, UPV measurements can give information on the progress of concrete strength.

Optimization of ready mixed concrete delivery for commercial batching plants of Ahmedabad, India

This paper is an attempt to develop a delivery schedule model with real time data for a commercial ready mixed concrete (RMC) plant in Ahmedabad city of Gujarat, India. Without a proper delivery schedule, either a truck-mixer would need to wait for the concrete to be placed at site or the construction site would need to wait for the truck-mixer to arrive on time. Developing an optimized dispatching and delivery sequence scheduling would improve the dispatching order of delivery of the RMC through truck-mixers from commercial batching plants to the respective construction sites. In the present research, this problem has been addressed through optimization techniques developed through mixed integer programming. Mixed integer programming considers both discrete and continuous variables which affect the delivery of RMC to the respective construction sites. The delivery scheduling problem was defined by identifying the objective function and the associated constraints. The mixed integer programming code was written with the help of MATLAB software. It has been observed after 101 iterations in MATLAB software that the dispatching sequence 1,2,2,1,1,3,2,3,2,3,3,3 has the least total waiting time of 155.4 min. After validating the same model with real time data, it has been observed that for the above dispatching sequence, the total waiting time is 153 min with one obstruction resulting in a delay of 48 min for the casting of concrete at site. Furthermore, based on the computations, it is recommended that the plant authorities need to increase the number of RMC truck-mixers from five to seven.

Optimization Of Cementitious Material Content For Sustainable Concrete Mixtures Through Value Engineering Approach

This paper studies the effectiveness of applying value engineering to actual concrete mixtures. The study was conducted in the State of Qatar on a number of strategic construction projects with international engineering specifications for the 2022 World Cup projects. The study examined the concrete mixtures of Doha Metro project and the development of KAHRAMAA’s (Qatar Electricity and Water Company) Abu Funtas Strategic Desalination Plant, in order to generally improve the quality and productivity of ready-mixed concrete used in construction and hydraulic projects. The application of value engineering to such concrete mixtures resulted in the following: • Improving the quality of concrete mixtures and increasing the durability of buildings in which they are used; • Reducing the waste of excess materials of concrete mixture, optimizing the use of resources, and enhancing sustainability; • Reducing the use of cement, thus reducing CO2 emissions which ensures the protection of environment and public health; • Reducing actual costs of concrete mixtures and, in turn, reducing the costs of construction projects; and • Increasing the market share and competitiveness of concrete producers. This research shows that applying the methodology of value engineering to ready-mixed concrete is an effective way to save around 5% of the total cost of concrete mixtures supplied to construction and hydraulic projects, improve the quality according to the technical requirements and as per the standards and specifications for ready-mixed concrete, improve the environmental impact, and promote sustainability.

Early risks identification on sources and causes waste road construction project materials

Waste material affects the road construction project consisting of ready mix concrete, lean concrete, B aggregate, landfill and cement. Identify risks by looking at the source and causes of waste material in the five materials. The source and causes of waste material for road construction do not yet exist. So it is necessary to take literature from a simplified building project so that it can be used for road construction projects with the help of experts. Risk identification is carried out with primary data, namely the questionnaire, then consulted by experts with the Delphi Method with three stages. The results of the Delphi method produce each of the causes of waste material for road construction projects that result in the identification of Early Risks.. Ready Mix concrete has 8 sources of waste material and 21 causes of waste material. Concrete Concrete has 7 sources of waste material and 18 causes of waste material. Aggregate B has 7 sources of waste material and 15 causes of waste material. Landfill has 8 sources of waste material and 26 causes of waste material. Cement has 7 sources of waste material and 31 causes of waste material.

Environmental Assessment of Ultra-High-Performance Concrete Using Carbon, Material, and Water Footprint.

There is a common understanding that the environmental impacts of construction materials should be significantly reduced. This article provides a comprehensive environmental assessment within Life Cycle Assessment (LCA) boundaries for Ultra-High-Performance Concrete (UHPC) in comparison with Conventional Concrete (CC), in terms of carbon, material, and water footprint. Environmental impacts are determined for the cradle-to-grave life cycle of the UHPC, considering precast and ready-mix concrete. The LCA shows that UHPC has higher environmental impacts per m3. When the functionality of UHPC is considered, at case study level, two design options of a bridge are tested, which use either totally CC (CC design) or CC enhanced with UHPC (UHPC design). The results show that the UHPC design could provide a reduction of 14%, 27%, and 43% of carbon, material, and water footprint, respectively.

PVC concrete composites: comparative study with other polymer concrete in terms of mechanical, thermal and electrical properties

Recycling PVC wastes with conventional chemical recycling methods such as pyrolysis, gasification is not feasible due to the carbon dioxide and dioxin emmissions generated with these methods. PVC wastes can be disposed using in ready-mixed concrete which is the most commonly used building material. In this study, effects of waste PVC instead of fine aggregate and the effects of waste PVC on the concrete properties were analyzed using 0%, 30%, 35%, 40% and 45% (w/w) in the experiments. Effects of waste PVC in concrete were compared with the other waste polymer concrete in terms of mechanical, thermal and electrical properties. All waste polymers have reduced the mechanical strength of concrete as expected. Improvement rates for the splitting tensile strength for 28 days are found to be 54.46%, 48.52% and 6.93% for PP, PET and rubberized concrete, respectively, in comparison with reference concrete. For thermal conductivity, improvement rates for 40% PC, 40% PP and 40% PVC concrete are found to be 52.56%, 44.87% and 42.31%, respectively. For electrical resistivity, the highest improvement rate was determined as 136.03%, 132.38% and 105.92% for PC, PVC and rubberized concrete, respectively.

Forecast of Ready Mix Concrete Operation By Neuralnetwork

In construction concrete place a major role, as the demand increases there is necessity for ready mix concrete (RMC) industry to cope up the demand.The Ready Mix Concrete (RMC) industry is growing due to the superior technical properties over normal concrete, but the potential is still huge. Concrete must be batched remotely and delivered to site by transit mixers. The productivity of ready mix concrete (RMC) placing is therefore of great important to the productivity improvement of the whole construction industry.An efficient RMC (Ready Mixed Concrete) delivering process becomes important to RMC batch plants. Because of time limitation of RMC delivery, the RMC plant manager usually needs to consider both timeliness and flexibility while matching up the working processes at various construction sites that call for RMC deliveries.Concrete production scheduling and truck dispatching is mainly handled manually by experienced RMCbatching plants staff. Various supply chain parameters detail of ready mix concrete (RMC) batching plant are considered for the prediction of productivity of the plant. This thesis provides an alternative way of tool which is applied to ready mix concrete operations to analyze the utilization, assignment of production and transportation resources. Use of software based model using Artificial Neural Network enables the RMC operator and construction site to effectively utilize the delivery sequence for optimal performance.

Study of Technical Specification Development for Ready-Mixed Concrete Type III Environmental Declarations

In order to address increasingly serious global environmental problems and intensified international trade barriers as well as the promotion of production processes by enterprises for the improvement of environmental impacts, Type III Environmental Declaration has emerged in response to the proper time and conditions and gradually developed into an important mean to solve environmental problems.This study, based on the principles and requirements stated in ISO 14025, takes ready-mixed concrete products as the example to discuss about the formulation of technical specifications for life cycle assessment of the ready-mixed concrete, in order to provide methodological basis and technical support for the formulation of technical specifications for the life cycle assessment of other domestic products as well as for the assessment of Type III Environmental Declaration.

Study on the Application of Recycled Fine Powder in Ready-Mixed Concrete

The basic properties of the fly ash, recycled brick powder and recycled concrete powder, compared the recycled brick powder and recycled concrete powder instead of fly ash in concrete preparation, influence on the working performance and mechanical properties; and through the modifier to improve the concrete slump loss is too large, analyzes the mechanism of change influence of modifiers on mechanical properties of concrete. The results showed that the recycled brick powder and recycled concrete powder in certain fineness conditions, its performance with fly ash; retarder, activator and some surfactant composition modifier has obvious effect on the working performance and mechanical properties; and hydration calcium silicate aluminum increased the role of large the mechanical properties of concrete.

The Effect of PM2.5 Exposure on Workers’ Enzymatic Superoxide Dismutase (SOD) Concentration at a Ready-Mix Concrete Factory in 2018

The lungs are exposed to PM2.5 via inhalation; PM2.5 then settles in the alveoli and circulates via the blood system, causing chronic obstructive pulmonary disease and cardiovascular issues. PM2.5 triggers the formation of superoxide anions and provide signals for the formation of superoxide dismutase. Workers at ready-mix concrete factories had long-term exposure to high doses of PM2.5. This study investigates the effects of PM2.5 on the blood SOD concentration of workers.

Effect of ettringite morphology on the properties of expanding cement systems

The effect of the pH of the reaction solution on the crystallization process and the ettringite morphology is theoretically substantiated and experimentally proved. Using physical and chemical research methods, the dependence of the morphology of crystallizing ettringite on the pH value of the reaction solution was established. It has been established that by introducing mineral micro fillers into the composition of expanding cement, it is possible to actively influence the pH value, the morphology of the resulting ettringite, the expansion kinetics, and the strength of cement stone and concrete based on it. The studies of the technical properties of concrete on the basis of expanding cements of various types have shown that with the introduction of micro fillers into the concrete composition, which intensify volume expansion during hydration of cement stone at the building site or factories for the production of ready-mixed concrete, it is possible to control the kinetics and extent of expansion, expansion pressure, deformative and strength characteristics of concrete and reinforced concrete structures.

THE EFFICIENCY OF PLASTICIZING SURFACTANTS IN ALKALI-ACTIVATED CEMENT MORTARS AND CONCRETES

Application of alkali-activated cements (AAC) allows to provide high quality functional and durable mortars and concretes in the view of efficient application of raw materials and energy supplies. There are five types of AACs depending on their composition. Thus the basic factor of AAC composition change can be considered as part of granulated blast furnace slag (GBFS) that changing from 0 % to 100 % in aluminosilicate component of cement. Compounds of alkaline metals are considered as AAC structurization components, which contents depend on AAC type. Functionality of mortars and concretes is regulated by surfactants, which act as plasticizing admixtures. However modification of AAC by admixtures has certain features connected with risk of molecular structure degradation in hydration medium of AAC due to alkaline hydrolysis (saponification). The emergence and speed of this process are determined first of all by AAC composition including nature (group) of alkaline component. The objective was to determine the chemical nature of plasticizers effective for property modification of mortars and concretes based on AACs with various content of GBFS (from 0 to 100 %) and appropriate alkaline component content. Stability of plasticizers’ molecular structure in hydrated medium of AAC with different content of GBFS was investigated by means of infrared spectroscopy. It was shown that admixtures with ester bonds undergo of molecular structure degradation as a result of alkaline hydrolysis at increasing pH values that is caused by content of alkaline component and depends on the nature of alkaline component. Admixtures without ester bonds (sodium lignosulphonate,ones based on polyethylene glycol and acyclic polyamine) are characterized by stability of molecule regardless of alkaline component content. The effective admixtures were used in dry mixes for anchoring (consistency of mortar 150 mm by Vicat cone; 1 d tensile strength in bending / compressive strength of mortar = 6,6 /30,6 MPа) and in ready-mixed concretes (consistency class changed from S1 to S3, S4 with consistency safety during 60 min; 3 d compressive strength of concrete was not less than the reference one without admixtures).

The Study of Influence of Ammonium Salts Additive on Efficiency of Ca2+ Extraction in Inorganic Carbonation Using Two forms of Ready Mixed Concrete (RMC) and MEA

The Study of Influence of Ammonium Salts Additive on Efficiency of Ca2+ Extraction in Inorganic Carbonation Using Two forms of Ready Mixed Concrete (RMC) and MEA

The Development of Construction Supply Chain Model on Ready Mix Concrete with Value Stream Mapping Method

The Development of Construction Supply Chain Model on Ready Mix Concrete with Value Stream Mapping Method