scholarly journals PENGARUH PENAMBAHAN BATU KARANG SEBAGAI SUBSTITUSI AGREGAT HALUS DALAMPEMBUATAN PAVING BLOCK

UKaRsT ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 35
Author(s):  
Edy Gardjito ◽  
Agata Iwan Candra ◽  
Yosef Cahyo

                                                              AbstractMaterial exploitation, especially the use of sand as the main component of concrete, needs to be reduced. The purpose of this research is to find out the value of compressive strength from the addition of rocks to achieve compressive strength according to the standard mix design of paving blocks. This research was conducted at the University's Civil Engineering Laboratory. Attending a trial and error method, the samples tested were cube with a size of 15 x 15 x 15 cm with 3 pieces with the quality of paving planned and K-225 or 18.675 MPa. The method of making specimens includes semi-mechanics using a concrete mixer. Fractional waste The rock is crushed into small pieces and then put in messin abrassion to get smaller pieces of rock and become grains of sand. Test result obtained a percentage of 25% indicating a compressive strength of 22.1 MPa, 20.3 MPa, 19.9MPa, and has an average value of 21.8 MPa. Then the results from the substitutionexperience i increase against compressive strength. Keywords: Coral, Fine Aggregate, Compressive Strength

Reactive Powder Concrete is a Concrete which does not have fine &coarse aggregate in it. It is due to the high cost in coarse aggregate and at the same time scarcity of the fine aggregate. RPC is also consists of fully a partially replacement of cement .so we are using partially replacement of cement. Where it is a special concrete and the microstructure is optimized by precise degree of all particles in the mix yield to maximum density. It consists of metakaolin, quartz-sand and cement. Here we are replacing coarse and fine aggregate by quartz-sand, and cement is partially replaced by metakaolin. And the percentage of meta kaolin is identified by trial and error method. In this we get the compressive, flexural & split tensile strength of RPC for 28 days


2012 ◽  
Vol 12 (2) ◽  
pp. 65-68
Author(s):  
I. Stachovec ◽  
M. Horáček ◽  
L. Zemčík ◽  
V. Kolda ◽  
J. Horenský

Gating Systems for Sizeable Castings from Al Alloys Cast into Ceramic Moulds In contrast to casting to conventional non-reusable "sand" moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly) on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all) any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.


2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Fatkhurrohim Fatkhurrohim ◽  
Ahmad Mashadi ◽  
Muhammad Amin ◽  
Dwi Sat Agus Yuwana

<p align="center">ABSTRACT</p><p>After the eruption of Mount Merapi, which occurred on October 26th 2010 produced an abundance of cold lava sand. The researcher attempted to conduct test of cold lava sand as fine aggregate concrete. This study aims to compare the compressive strength of concrete by using a cold lava sand taken from the Kali Putih, Salam, Magelang and sand are not affected by cold lava taken from Kali Blondo located in the Blondo, Magelang. The method of this study include: testing of materials, manufacturing of test specimens and test concrete performance after 7, 14, 21 days and 28 days. From the test result of concrete compressive strength we can know strength combaine ineach mixtureby weight volume ratio 1pc: 2 ps; 3kr with 0,6 water cement ratio. Based on the results of testing the quality of the sand material taken from the Kali Putih, Salam, Magelang to the mud content, unit weight, specific gravity, water absorption,and sieve analysis PUBI 1982 qualifies mixed concrete.The result of comparative testing of the quality of the sand material taken from kali blondo to sieve analysis are not eligible PUBI 1982. The results showed that the compressive strength of concrete on average, the highest shown in the concrete that uses cod lava sand derived from the down stream of Kali Putih, the average compressive strength of 279,51 kg/cm2, with the weight of the specimen by an average of 11, 5 kg.</p>


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4481
Author(s):  
Yungho Leu ◽  
Chia-Ming Lin

Luminance is an essential quality of a TFT-LCD display. Manufacturers have attempted to improve the soft-to-hard lamination stage to enhance the luminance of their TFT-LCD displays. In addition, many customers have complained about the insufficient luminance of the TFT-LCD displays of the case company. While product engineers have kept tuning the control factors in the soft-to-hard lamination stage through the trial and error method, the improvement of the luminance was not good enough. This study aims to assist the product engineers to fine-tune the settings of the control factors using a new method composed of the Taguchi method, a neural network, and a genetic algorithm. The confirmation experiments showed that the proposed method had increased the average luminance of the TFT-LCD displays from 17.03 to 25.15, which was higher than the required luminance value of 25. As a result, the number of complaints on the TFT-LCD displays had been significantly reduced.


2021 ◽  
Vol 21 (3) ◽  
pp. 129-138
Author(s):  

Normal concrete uses fine aggregate and coarse aggregate with concrete density 2200 kg/m3-2400 kg/m3 with a compressive strength of about 15-40 MPa [1]. The purpose of this study is to determine characteristics of the concrete aggregate and the compressive strength of the concrete design based on the DOE (Department of Environment) method and the SNI Standard. In this research, the use of nugmet shell was varied as follows: 0%, 0,25%, 0,50%, 0,75% and 1% of the cement weight. The results showed that the use of nutmeg shells as a normal concrete affected the specific gravity and the value compressive strength of concrete. The higher the percentage of nutmeg shells, the lower the specific gravity and compressive strength of the concrete. The average value of density to nutmeg shell concrete (NSC) 2254.72 (kg/m3) and normal concrete 2304.32 (kg/m3). The compressive strength of normal concrete is 224.2 kg/cm2 and the nutmeg shell concrete (NSC) the composition of 0.25% and 0.5% obtained by 129.6 kg/cm2 and 140.0 kg/cm2 increases the use of nutmeg shell 0.75% and 1% obtained value ​​of 117.6 kg/cm2 and 118.1 kg/cm2 decreased at the age of 28 days. The compressive strength of normal concrete 22 MPa while the maximum nutmeg shell concrete (NSC) 14 MPa, so it does not meet the quality of normal concrete in general.


Author(s):  
Lidiya Derbenyova

The article focuses on the problems of translation in the field of hermeneutics, understood as a methodology in the activity of an interpreter, the doctrine of the interpretation of texts, as a component of the transmission of information in a communicative aspect. The relevance of the study is caused by the special attention of modern linguistics to the under-researched issues of hermeneutics related to the problems of transmission of foreign language text semantics in translation. The process of translation in the aspect of hermeneutics is regarded as the optimum search and decision-making process, which corresponds to a specific set of functional criteria of translation, which can take many divergent forms. The translator carries out a number of specific translation activities: the choice of linguistic means and means of expression in the translation language, replacement and compensation of nonequivalent units. The search for the optimal solution itself is carried out using the “trial and error” method. The translator always acts as an interpreter. Within the boundaries of a individual utterance, it must be mentally reconstructed as conceptual situations, the mentally linguistic actions of the author, which are verbalized in this text.


Author(s):  
H. J. Godwin

The determination of a pair of fundamental units in a totally real cubic field involves two operations—finding a pair of independent units (i.e. such that neither is a power of the other) and from these a pair of fundamental units (i.e. a pair ε1; ε2 such that every unit of the field is of the form with rational integral m, n). The first operation may be accomplished by exploring regions of the integral lattice in which two conjugates are small or else by factorizing small primes and comparing different factorizations—a trial-and-error method, but often a quick one. The second operation is accomplished by obtaining inequalities which must be satisfied by a fundamental unit and its conjugates and finding whether or not a unit exists satisfying these inequalities. Recently Billevitch ((1), (2)) has given a method, of the nature of an extension of the first method mentioned above, which involves less work on the second operation but no less on the first.


2016 ◽  
Vol 4 (29) ◽  
pp. 11446-11452 ◽  
Author(s):  
Zhonglu Guo ◽  
Jian Zhou ◽  
Linggang Zhu ◽  
Zhimei Sun

Identifying suitable photocatalysts for photocatalytic water splitting to produce hydrogen fuelviasunlight is an arduous task by the traditional trial-and-error method.


2009 ◽  
Vol 424 ◽  
pp. 197-204 ◽  
Author(s):  
W. Assaad ◽  
H.J.M. Geijselaers ◽  
K.E. Nilsen

The design of extrusion dies depends on the experience of the designer. After the die has been manufactured, it is tested during an extrusion process and machined several times until it works properly. The die is designed by a trial and error method which is expensive interms of time consumption and the amount of scrap. Research is going on to replace the trial pressing with finite element simulations that concentrate on material and tool analysis. In order to validate the tool simulations, an experiment is required for measuring the deformation of the die. Measuring the deformation of the die is faced with two main obstacles: high temperature and little free space. To overcome these obstacles a method is tried, which works by applying a laser beam on a reflecting surface. This cheap method is simple, robust and gives good results. This paper describes measuring the deformation of a flat die used to extrude a single U shape profile. In addition, finite element calculation of the die is performed. Finally, a comparison is performed between experimental and numerical results.


1969 ◽  
Vol 23 (2) ◽  
pp. 128-132 ◽  
Author(s):  
E. Alexander ◽  
B. S. Fraenkel

A routine method to adjust a grazing incidence spectrometer for maximum resolution is described. The trial and error method uses as variable, the distance of the slit from the Rowland circle. Examples of resolved doublets are shown.


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