KURVATEK

THE IMPORTANCE OF BRICKS AND MORTAR IN DETERMINING THE STRENGTH OF MASONRY WALLS

2024-04-17T19:15:58+07:00

Brick masonry walls are a type of construction that is in great demand, because the material is easy to obtain at a cheap price. Additionally, the process does not require any special skills. The strength of the wall is greatly influenced by the strength of the materials that make it up, namely bricks and mortar as adhesive. The role of bricks and mortar in creating wall strength needs to be investigated for their effectiveness. This research aims to obtain an overview of the effectiveness of the role of bricks or mortar in forming the compressive strength of masonry walls. To get the illustration in question, a compressive strength test of mortar, brick and masonry walls was carried out which was represented by masonry prism test objects referring to ASTM C1314-07. The test results are then compared to get an idea of the relationship between the three. From the research results it can be concluded that the compressive strength of masonry walls is determined more by the compressive strength of the bricks, but is also influenced by the compressive strength of the mortar. The higher the compressive strength of the mortar, the compressive strength of the wall will increase, but it is not significant. Therefore, the use of high strength mortar is less effective in increasing wall strength.

THE INFLUENCE OF URBANIZATION TO THE WATER INFILTRATION ZONE ON BANYUMANIK SUB-DISTRICT, SEMARANG CITY, CENTRAL JAVA, INDONESIA

2024-04-16T08:13:33+07:00

The high growth of developed land in the Banyumanik Sub-District, especially in residential and commercial areas, occurred due to the high demand for housing, lifestyle fulfillment, and speculation and investment by the upper-middle-class society. The reduction or loss of land with vegetation cover in the Banyumanik Sub-District increases the potential for flooding due to more significant surface runoff than water absorption during heavy rainfall. This research used integrated spatial analysis to generate information on the critical level of water infiltration in the research area using the Analytical Hierarchy Process (AHP) method. Both primary and secondary data collected will be compiled and subjected to spatial analysis to address the issues at hand. The weight of each parameter class produced by the AHP method is used for modeling and includes infiltration rate, land use, slope, and lithology parameters. The criticality level of the water infiltration zone in the southern part of Banyumanik Sub-District indicates that the water infiltration condition in the research area consists of good class at 13.589%, naturally normal at 18.405%, started to be critical at 16.114%, slightly critical at 20.764%, critical at 18.286%, and very critical at 12.841%. Changes in land use in the research area have become the primary factors causing alterations in the water infiltration conditions. Infiltration wells are one of the solutions to mitigate runoff as part of sustainable rainwater management. The government plays a crucial role as a policymaker in making decisions to address issues related to urban area development towards sustainable development.

The THE EFFECT OF GEOLOGICAL STRUCTURES ON THE COAL QUALITY OF THE SEMBAKUNG FORMATION IN BERAU REGENCY, EAST KALIMANTAN

2024-04-17T19:20:55+07:00

The Subsurface coal resources are 43.533 billion tons with total reserves of 173.51 million tons. The Berau Regency area has coal-bearing formations of the bituminous - sub bituminous type, namely the Latih Formation, Labanan Formation, Domaring Formation, Sajau Formation and Sembakung Formation. The research methods used are surface geological mapping, rock sampling and drilling. The analysis used is coal quality and geological structure. The results of analysis of changes in the dip of rock layers caused by geological structures in the form of folds and thrust faults can cause changes in coal quality. The dip of coal seam in the LP 54 outcrop sample is 24º, which has lower coal quality compared to LP 38 that has a seam dip of 65º. The quality of coal in LP 38 seam position N 203º E/65º has a calorific value of 6,393 Kcal/kg, while in LP 54 seam position N 30º E/24º has a calorific value of 4,888 Kcal/kg. At the drill point, location MMA_19-T has better coal quality compared to MMA_18-T and MMA_20-T, this is because the seam in MMA_19-T experienced folding accompanied by faulting with a calorific value of 7326 Kcal/kg.

An ANALYSIS OF DVB-T2 TV BROADCAST TESTING DRIVE TEST AND FIELD STRENGTH METHODS IN THE JAKARTA SERVICE AREA

2024-04-17T14:36:13+07:00

Indonesia has adopted DVB-T2 as the technology standard for terrestrial digital television broadcasting. This research aims to test and analyze the reception quality of DVB-T2 TV broadcasts in the DKI Jakarta service area. The research was conducted using drive test and field strength methods to test and evaluate the quality of digital television broadcasts. Tests were conducted in various locations in the DKI Jakarta service area using the Gsertel Hexylon TV Analyzer technical device to test DVB-T2 TV broadcast signals. The field strength test results were more accurate and higher values were generated than the drive test. Several parameters such as signal level and MER are evaluated and analyzed to find out what affects their values. The transmitter parameter settings such as modulation, FEC code rate, FFT Mode, Guard Interval, and Pilot Pattern greatly affect the signal level and MER values. The optimization performed on CH 24 also managed to maintain its signal level value of 18.19 dB and its MER of 55.01 dBµV to maintain broadcast stability during a technical failure of the transmitter on CH 1.

ANALYSIS OF ROCK QUALITY AND LANDSLIDE POTENTIAL IN NORTH JERING HILLS, SLEMAN, YOGYAKARTA

2024-04-17T19:25:14+07:00

The study was to identify the direction and type of potential landslides, as well as assess the rock quality on the slopes of North Jering Hills. The scanline method, consisting of stretching the meter, was employed to collect data on the plane of failure. The information gathered encompassed the direction, slope level, and condition of the unsuccessful plane, aligned with the parameters in the RMR table of Bieniawski from 1989. Following the collation of data, kinematic and rock mass quality analysis was undertaken using stereographic projection and RMR parameter weighting respectively. The kinematic analysis revealed a planar avalanche type on the slope. The RMR value of the research location's slope was 80, classifying it as good rock.

EFFECT OF USING LIME AND FLY ASH AS A CEMENT SUBSTITUTE FOR SOIL STABILITY

2024-04-19T16:48:55+07:00

Subgrade is the lowest layer that receives the load on it if it does not have carrying capacity that is allowed then need for soil stabilization. Chemical soil stabilization is often done with the addition of cement but the use of cement material will cost quite high, it is necessary to alternate other materials for the substitution of cement to reduce the implementation costs incurred. Cement will be replaced as a stabilizing material in this research with additional materials like lime and fly ash. In this research, soil material was taken from the Sentul – Karawang Toll Road Project STA 24+300, with fly ash from PT PUSRI as the stabilization material, and lime material obtained from the market in Yogyakarta. The stabilization material will be used with a fixed lime percentage of 4.2% of the dry weight of the soil, and fly ash at 1.4%, 2.1%, 2.8%, 3.5%, and 4.2% of the dry weight of the soil. The soil samples were tested for physical and mechanical properties, including Standard Proctor and California Bearing Ratio (CBR). All test results were compared to select one variation, which was then designated as the Optimum Mix Design (OMD) sample. The test results of the soil sample + 4.2% lime + 2.1% fly ash yielded a CBR value of 15.52%, indicating an increase of 1078.02% from the initial 1.44%, and were formally designated as an OMD sample. The CBR value satisfies the subgrade requirements, namely >6%.

OPTIMIZATION OF THE PERFORMANCE OF THE SANDSTONE CRUSHING PLANT UNIT AT PT PULAU LEMON

2024-04-18T21:23:28+07:00

The process of processing sandstone material at the PT Pulau Lemon crushing unit is not yet optimal. This is due to differences in the amount of material entering and leaving the crushing unit. To optimize the performance of the processing unit, it is necessary to conduct research on the causes of material loss. Furthermore, the research aims to: 1) calculate material loss; 2) assess the causes of material loss and determine efforts to minimize material loss. The research was carried out using mathematical calculations using mass balance equations for material entering and leaving the processing unit, field observations and interviews. The research results showed that the amount of incoming material was 16.66 tons/day and outgoing material was 14.85 tons/day, so the material lost was 1.81 tons/day. or 10.80%. Material loss is caused by the slope of the conveyor belt being less than gentle and some parts being torn, wind, rain and mechanical problems. Efforts to optimize the performance of processing units include reducing waiting times, regularly checking and repairing equipment, and installing roofs.

ANALYSIS OF THE EXISTENCE OF GEOTHERMAL MANIFESTATIONS USING FAULT FRACTURE DENSITY (FFD) IN TEMPURAN DISTRICT, MAGELANG REGENCY

2024-04-19T08:42:12+07:00

Being in an active fire lane means that Indonesia has geothermal potential. The geothermal research location is in the Tempuran area, Magelang Regency. The method used is by using alignment in the National Digital Elevation Model (DEMNas) data and calculating it using the Fault Fracture Density (FFD) method, the result of which is a contour map. This research aims to identify the existence of geothermal manifestations with FFD values. The research results show that the FFD value in the Tempuran geothermal manifestation area varies between 0.09 - 1.80 km/km2. The FFD value shows that the Tempuran geothermal manifestation is in a low density zone. There is no direct correlation between the presence of geothermal manifestations and the FFD value. The Tempuran geothermal manifestation is thought to be related to geological formations composed of volcanic rock and related to an aquifer system, as well as faults that trend northwest-southeast.

ALTERATION AND MINERALIZATION STUDIES IN THE JEBLOGAN AREA, KARANGTENGAH, WONOGIRI, CENTRAL JAVA

2024-04-17T09:51:00+07:00

The research area is located in Jeblogan, Karangtengah, Wonogiri, Central Java. This study aims to investigate the hydrothermal alteration and mineralization. Geological structures present in the research area include faults and fractures. These faults are well-developed trending NE-SW, NW-SE, and N-S as pathways for fluid ascent to the surface, thereby influencing alteration patterns. Mineral alteration assemblages in the research area, based on petrographic, mineragraphy, and XRD analysis, result from hydrothermal processes and include mineral assemblage zones such as Quartz ± Silica ± Pyrite, Alunite + Pyrophyllite ± Zunyite ± Quartz ± Hematite, Illite + Halloysite ± Smectite ± Kaolinite ± Quartz, and Chlorite + Calcite + Epidote ± Pyrite. Mineralization found in the research area includes Chalcopyrite, Sphalerite, Pyrite, Chalcocite, and Galena. Based on the characteristic parameters of the deposit type and laboratory analysis, the deposit type at the research location is low-sulfidation epithermal deposit and intermediate-sulfidation deposit.

THE CRITICAL LEVEL OF WATER INFILTRATION MAPPING IN GUNUNGPATI SUB-DISTRICTS, SEMARANG CITY

2024-04-18T13:50:30+07:00

One of the reasons for the rapid population growth in the 21st century is urbanization. This leads to land degradation, which can result in a lack of water seeping into the ground when it rains in densely developed areas. Most of the water becomes surface runoff that cannot be absorbed by the soil because the runoff exceeds the soil's capacity to absorb water. In response to this situation, research was conducted on the criticality level of water catchment areas in Gunungpati District, Semarang City. The research involved collecting primary data through infiltration rates and lithology taken in the field, as well as secondary data, including information on land use and slope. This data was later verified in the area. The collected data were then analyzed using the Analytical Hierarchy Process (AHP) method by assigning weights to each parameter and sub-parameter. The parameters considered were land use, infiltration rate, slope, and lithology. The weighted values were overlaid to generate a critical level zoning map of water catchment areas in Gunungpati District, Semarang City. The critical level of water catchment areas in the research area can be categorized into "good" with an area of 1307.2 Ha, "normal natural" with an area of 1013.12 Ha, "starting to be critical" with an area of 436.26 Ha, "Slightly critical" with an area of 91.87 Ha, and "critical" with an area of 7.89 Ha, out of a total research area of 2856.34 Ha..

SIZE DISTRIBUTION OF JAW CRUSHER CRUSHING PRODUCTS FOR ROUNDED MATERIAL

2024-04-26T21:16:19+07:00

Abstract — Crushing is one of stage material size reduction in mineral processing. Jaw Crusher is one of the equipment that used to reduction size material and it’s generally used in primary crushing. Feed of crushing is come from mined material (Run of Mine-ROM) that have various shapes like very rounded, rounded, angular etc. Rounded material is one of them. The aim of this research is to calculate the size distribution and the pattern of size distribution product of crushing for rounded material. The equipment of crushing in this research was used Jaw Crusher in Mineral Processing Laboratory, Institut Teknologi Nasional Yogyakarta which 30 samples material. The same pattern of size distribution was obtained from the +4#, -4#+10#, -10#+20#, -20#+40#, -40#+60#, -60#+100#, -100#+200# dan -200# product size distribution. The biggest amount of size distribution was obtained in 4#. Limiting Reduction Ratio (LRR) were distributed in range 4-6. Losses percentage (% losses) of material crushing were less than 10%.

Keywords: Crushing, limiting reduction ratio, losses, mineral processing, primary

THE EFFECT OF ADDING WASTE TIRE RUBBER POWDER ON PAVING BLOCK WEAR

2024-04-19T08:34:51+07:00

Pavement using paving blocks is the right choice because of its easy installation and maintenance. One form is a quadrilateral type that is widely used for environmental and pedestrian roads. With good road access being one of the improvements in vehicles so that waste tires also increase, solutions are needed to reduce the impact on the environment but are also expected to provide benefits for paving block roads, especially increasing adhesion between paving block constituent materials. Based on this background, it was a research idea with the aim of determining the effect of adding waste tire rubber powder on the wear resistance of paving blocks. Research method with strength testing on paving block samples with a size of 5 cm x 5 cm x 2 cm a total of 18 samples. The results showed the average strength value of paving blocks with a mixture of waste tire rubber of 1%, 2%, 3%, 4%, 5% of 0.134, 0.223.0235, 0.246 and 0.247 mm / minute, so that the addition of waste tire rubber powder showed a decrease in the wear rate of paving blocks.