scholarly journals Optimizing Flexural Strength of Concrete Fc’ 14,5 MPa Using Acetylene Welding Carbide Waste

UKaRsT ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 220
Author(s):  
Bobby Damara ◽  
Sugeng Dwi Hartantyo

Replacing the main material using unused materials such as hazardous waste can be utilized in concrete innovation. One of the hazardous wastes that can utilize the waste generated from the acetylene welding process. The waste has hardening properties when exposed to water. Its properties are almost the same as cement can replace or add part of the cement mixture. Conducted this research was to determine the effect of using carbide waste from the acetylene welding process on the flexural strength of concrete. The experimental method is carried out by making test objects in the laboratory. The proportions of waste added were 7%, 10%, and 12% by weight of cement. The test object used is in the form of a beam with dimensions of 60 cm x 15 cm x 15 cm. The planned initial quality is concrete F'c 14.5 MPa (K175). The flexural strength test was carried out at the age of 27 days of concrete. From the results of the research carried out, it is found that the use of carbide waste from the acetylene welding process has not been able to improve the quality of concrete significantly. The highest flexural strength was obtained from waste at 7%, with a flexural strength value of 9.692 Mpa. So from these results, it can be used as a reference in the utilization of carbide waste from the acetylene welding process.

Jurnal CIVILA ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 213
Author(s):  
Asrul Majid ◽  
Hammam Rofiqi Agustapraja

Infrastructure development is one of the important aspects of the progress of a country where most of the constituents of infrastructure are concrete. The most important constituent of concrete is cement because its function is to bind other concrete materials so that it can form a hard mass. The large number of developments using cement as a building material will leave quite a lot of cement bags.In this study, the authors conducted research on the effect of adding cement waste to the compressive strength of concrete. This study used an experimental method with a total of 24 test objects. The test object is in the form of a concrete cylinder with a diameter of 15 cm and a height of 30 cm and uses variations in the composition of the addition of cement waste cement as a substitute for fine aggregate, namely 0%, 2%, 4% and 6%. K200). The compressive strength test was carried out at the age of 7 days and 28 days.The test results show that the use of waste as a partial substitute for fine aggregate results in a decrease in the compressive strength of each mixture. at the age of 7 days the variation of 2% is 16.84 MPa, 4% is 11.32 MPa and for a mixture of 6% is 6.68 MPa. Meanwhile, the compressive strength test value of 28 days old concrete in each mixture decreased by ± 6 MPa. So the conclusion is cement cement waste cannot be used as a substitute for fine aggregate in fc 16.6 (K200) quality concrete because the value is lower than the specified minimum of 16.6 MPa.


2021 ◽  
Vol 3 (3) ◽  
pp. 49-61
Author(s):  
Meisye Mitha Siranga ◽  
Suryanti Rapang Tonapa ◽  
Frans Phengkarsa

The use of concrete in Indonesia cannot be separated from skyscrapers, bridges with long spans, and underground buildings which generally have a larger load, so the use of high-strength concrete is necessary. This study aims to determine the value of compressive strength, split tensile strength, flexural strength, modulus of elasticity of concrete and determine the workability of fresh concrete with the addition of 0.8% superplaticizer. The test objects used in the form of cylinders with a diameter of 15 cm and a height of 30 cm as many as 15 pieces, and 3 pieces of blocks measuring 15 cm × 15 cm × 60 cm. From the results of the study, the compressive strength value was 43,007 MPa. The split tensile strength test is 3.584 MPa. The flexural strength test is 4,340 MPa. The elastic modulus test is 28447.956 MPa. From the slump test on fresh concrete with the addition of a superplaticizer, it is obtained by 10 cm.


2020 ◽  
Vol 11 (2) ◽  
pp. 61-71
Author(s):  
Yulizar Yusuf ◽  
Vivin Firman Savitri ◽  
Hermansyah Aziz

The aim of this study is to utilize fly ash from various sources on chemical and physical properties of cement type I (OPC). Utilization of fly ash can improve the strengthness of the cement. It can reduce the waste of fly ash by utilization into cement process. The procedure has been carried out on cement type I (OPC) with the addition of fly ash additives from various sources with concentration variations such as 10% and 20%. Utilization of fly ash as additives substance in cement works to improve the quality of cement. The main parameter in determining the quality of cement is determined by the compressive strength. The results of the compressive strength test showed that the addition of fly ash with a concentration of 10% had a higher effect on the compressive strength than the addition of a concentration of 20%. 5 types fly ash from various sources, fly ash from PT Sinar Mas gives greater compressive strength at 28 days. the addition of fly ash additives to OPC cement mixture has chemical and physical properties which are not much different from properties of PCC cement.


Author(s):  
Marzieh Khanbeigi ◽  
Taleb Askaripoor ◽  
Hamidreza Nassehinia ◽  
Bahareh Moradi

Introduction: In recent years, unauthorized disposal of the hazardous wastes has threatened the human health and created many environmental problems in human societies. Given the direct and indirect hazards of these wastes, it is essential to collect information with regard to their appropriate management in Iran. The purpose of this study was to determine the quantity and quality of the hazardous waste and its management in industries of Damghan City in Iran. Methods: Initially, the list of industries in Damghan City was prepared. Later, the necessary coordination was made with the relevant organizations and active units were identified. After the field tours, information on the quality, quantity, and management of the hazardous wastes was collected by a questionnaire.  Results: The results showed that the total hazardous waste products in the investigated industries were 4795 kg per month; 36.36% of the industries produced toxic substances, 9.09% created corrosive substances, 36.36% flammable materials, and 18.18% resulted in reactive substances. None of the studied industrial units had a control system after disposal of the industrial hazardous waste. Furthermore, only 36.36% of the industries had specialized staff to collect and dispose the hazardous waste. Conclusion: To prevent environmental pollution and preserve the human health, a proper management system should be established for organizing the industrial wastes. Furthermore, identifying and gathering information about the industrial processes, raw materials, and waste products can be very useful in managing hazardous industrial wastes.  


2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.


2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2139
Author(s):  
Wei Shian Tey ◽  
Chao Cai ◽  
Kun Zhou

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.


2010 ◽  
Vol 160-162 ◽  
pp. 974-979
Author(s):  
Nai Feng Fan ◽  
Zhen Luo ◽  
Yang Li ◽  
Wen Bo Xuan

Resistance spot welding (RSW) is an important welding process in modern industrial production, and the quality of welding nugget determines the strength of products to a large extent. Limited by the level of RSW quality monitor, however, RSW has rarely been applied to the fields with high welding quality requirements. Associated with the inversion theory, in this paper, an electromagnetic inverse model of RSW was established, and the analysis of influence factors, such as the layout of the probes, the discrete program and the regularization method, was implemented as well. The result shows that the layout of the probe and the regularization method has great influence on the model. When the probe is located at the y direction of x-axis or the x direction of y-axis and Conjugate Gradient method is selected, a much better outcome can be achieved.


2010 ◽  
Vol 20-23 ◽  
pp. 1385-1390
Author(s):  
Hong Bin Yang ◽  
Xiao Hong Wang ◽  
Zong De Fang

To develop a good quality of hypoid gear drive, the authors test the vibration and noise of two kinds of hypoid gear drives under different working conditions. The test object is a pair of hypoid gear drive used in the back axle of one minivan and a designed hypoid gear drive with high teeth based on the former. The results indicate that the hypoid gear drive with high teeth has lower vibration and noise.


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