• Computers and Concrete
• /
• v.17 no.3
• /
• pp.423-433
• /
• 2016

After the industrial of steelmaking by-products are processed properly, they can be used in civil engineering, not only as a substitute for natural resources and to reduce costs, but also to provide environmental protection. This study used different amounts (10%, 20%, 30%, 40%,and 50%) of desulphurization slag to replace natural fine aggregates in ready-mixed soil materials, and tested the physical and fresh properties (slump, slump flow, tube flow, initial setting time, and bleeding) and hardened properties (compressive strength, ball drop, ultrasonic pulse velocity) of the materials. The variations between the performances of the materials with different mix proportions were discussed. When desulphurization slag is used in RMSM, the workability can be enhanced obviously significantly. When the replacement of desulphurization slag is 50%, the slump flow is increased by 110mm compared with the control group, and the initial setting time increases as the replacement increases, because of bleeding. When the replacement is 10% and 20%, the compressive strength at various ages is higher than that of the control group. When the replacement is 10%, the compressive strength at 7 days is higher than that of the control group by 60%, and the ultrasonic pulse velocity is proportional to the compressive strength, which increases with age and decrease as the replacement increases. An appropriate replacement can effectively accelerate construction, and allow projects to be finished ahead of schedule; therefore, an appropriate replacement, is applicable for ready-mixed soil materials.

• Computers and Concrete
• /
• v.12 no.6
• /
• pp.785-802
• /
• 2013

Ready-mixed soil material, known as a kind of controlled low-strength material, is a new way of soil cement combination. It can be used as backfill materials. In this paper, artificial neural network and nonlinear regression approach were applied to predict the compressive strength of ready-mixed soil material containing Portland cement, slag, sand, and soil in mixture. The data used for analyzing were obtained from our testing program. In the experiment, we carried out a mix design with three proportions of sand to soil (e.g., 6:4, 5:5, and 4:6). In addition, blast furnace slag partially replaced cement to improve workability, whereas the water-to-binder ratio was fixed. Testing was conducted on samples to estimate its engineering properties as per ASTM such as flowability, strength, and pulse velocity. Based on testing data, the empirical pulse velocity-strength correlation was established by regression method. Next, three topologies of neural network were developed to predict the strength, namely ANN-I, ANN-II, and ANN-III. The first two models are back-propagation feed-forward networks, and the other one is radial basis neural network. The results show that the compressive strength of ready-mixed soil material can be well-predicted from neural networks. Among all currently proposed neural network models, the ANN-I gives the best prediction because it is closest to the actual strength. Moreover, considering combination of pulse velocity and other factors, viz. curing time, and material contents in mixture, the proposed neural networks offer better evaluation than interpolated from pulse velocity only.

• Journal of the Korea Concrete Institute
• /
• v.15 no.3
• /
• pp.386-391
• /
• 2003

Ready mixed mortar has been originated from lime industry of Germany and is being used widely in the world at present. In recent years, the studies of mortar with new faculty have been progressed. In this study, we used elvan instead of using sand in order to make cement mortar and investigated characteristics of elvan and mortar that used elvan. The major compositions of elvan were $SiO_2$ and $Al_2O_3$. The crystal phases of elvan were composed of quartz and sillimanite. Elvan had a lot of pore and absorption ratio was 2.09%. The compressive strength of mortar that used elvan satisfied korean industrial standards under 1:3 (mixing ratio) and water retentivity increased according to increase of elvan contents. Far infrared radiation and deodorization ratio increased and thermal conductivity decreased according to increase of elvan contents.

• Magazine of RCR
• /
• v.14 no.2
• /
• pp.48-53
• /
• 2019

• Journal of the Korean Society of Industry Convergence
• /
• v.5 no.2
• /
• pp.103-110
• /
• 2002

An artificial neural network is applied to the prediction of compressive strength, slump value of concrete. Standard mixed tables arc trained and estimated, and the results are compared with those of experiments. To consider the varieties of material properties, the standard mixed tables of two companies of Ready Mixed Concrete are used. And they are trained with the neural network. In this paper, standard back propagation network is used. For the arrangement on the approval of prediction of compressive strength and slump value, the standard compressive strength of 210, $240kgf/cm^2$ and target slump value of 12, 15cm are used because the amount of production of that range arc the most at ordinary companies. In results, in the prediction of compressive strength and slump value, the predicted values are converged well to those of standard mixed tables at the target error of 0.10, 0.05, 0.001 regardless of two companies.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.177-180
• /
• 2002

This study is performed to properties of ready mixed concrete (RMC) in site. The unit weight of the B company's RMC is range from $2,308kg/m^3\;to\;2,355kg/m^3$ and that of the J company's RMC is range from $2,288kg/m^3\;to\;2,310kg/m^3$. The compressive strength of B company's RMC of curing age of 7 days is range from $191kgf/cm^2-232kgf/cm^2$ and that of curing age of 28days is $273kgf/cm^2{\sim}306kg/cm^2$. The compressive strength of J company's RMC of curing age of 7 days is range from $151kgf/cm^2{\sim}177kgf/cm^2$ and that curing age of 28 days is range from $215kgf/cm^2{\sim}234kgf/cm^2$. The B and J company's air content is range of $3.2{\sim}5.2%$. The content of Chloride of the Band J company's is range from each $0.026kg/m^3{\sim}0.046kg/m^3\;and\; 0.034kg/m^3{\sim}0.069kg/m^3$, respectively.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.140-144
• /
• 2004

Barcode system has been used for many years in labors controlling & ready mixed concrete supplement in A/E/C industry However, it was not quite successful because ot its limitations in the field. The use of RFID system is getting important in the real world. RFID system substituted for barcode system in labor controling & ready mixed concrete supplement and it showed its potentialities in other major materials supply logistics and its possibilities In progress management of 4D system. This research shows RFID system's case study and its future directions in A/E/C industry.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.5
• /
• pp.468-481
• /
• 2011

This research presents a strategy and information system to manage the logistics of delivery ready mixed concrete (RMC) under the integrated environment of PMIS+RFID. PMIS is system tool and technique used in construction sectors to delivery information. Information that can be extracted electronically in real time is more valuable than data gathered and maintained manually. RFID technology can help to improve data accuracy through supply chains and by identifying products and objects at specific points through automatic identification. The objectives of these two implementations can be able to improve the efficiency of logistics management for RMC truck process, and to verify the technical and practical feasibility of PMIS+RFID application in construction industry. This may be realistic given the dynamics of daily activities on construction sites. This research is focused on examples on real world case study, applications and research theme related and connected to PMIS+RFID technology. It demonstrated that PMIS+RFID technology has been automatically implemented and has shown process information about the RMC truck and the overall status information about it, both quickly and accurately. As a result, the construction site where needs 300 $m^3$ pouring (50 RMC trucks) per day can be reduced total 250 minutes. Moreover, this time saving is related to the labour cost saving. From the case studies, RFID+PMIS system was proven in terms of effectiveness rather than current method.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1993.10a
• /
• pp.138-143
• /
• 1993

The objective of this report is to investigate the effect of factors like the fineness modulus of sand , content of fly ash and slaked lime, binder/sand ratio, admixture dosage on the physical properties of mortar for finishing. The analysis was performed with design of experiment and air content, water retention and compressive strength were measured.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.11
• /
• pp.803-808
• /
• 2013

The purpose of this study was performed to investigate the optimum conditions of pH, concrete sludge, seed dosage, mixing intensity, operation time in treating fluoride-containing wastewater as $CaF_2$ using the ready-mixed concrete sludge. Considering fluoride removal, water content, that pH 6, concrete sludge dosage of 10 g/L, Seed dosage ($CaF_2$) of 2 g/L, mixing intensity of 100 rpm and operation time of 60 min were found to be optimum. Correspondingly, removal of fluoride and water content was about 85% and 64%, respectively. Increase in amount of seed dosage did not affect fluoride removal efficiency. but the result that the water content is decreased was shown up in occuring the solid-liquid separation well.