Field Validation for the Constructability of Exposed Aggregate Concrete Overlay

Functional performance of existing concrete pavement is necessarily improved to maintain the low tire-pavement noise and the long-term skid resistance. Thus, exposed aggregate concrete overlay is introduced since these high functional performances are expected. Its surface texture requires the removal of cement mortar to expose the aggregates. This technique results a durable surface texture and an effective surface drainage through the random shape of aggregates. In Korea, concrete overlay is allowed to construct between 200 and 400 meters per day. This concrete amount is insufficient to use batch plant. Therefore, mobile mixer is employed to supply a consistent quality and on-time production. In addition, surface texture of this overlay method is significantly related to the reduction of tire-pavement noise. Accordingly, outcome of surface texture should be validated in the real field construction. This study intended to verify the constructability of exposed aggregate concrete overlay using mobile mixer for concrete production and deck finisher for concrete placement to acquire the surface texture and structural strengths. Surface texture and concrete strengths from mock-up and laboratory tests were measured and compared with design criteria. This research indicated that the suggested equipment and construction procedure can efficiently maintain the required surface texture of EACO for low tire-pavement noise and the adequate strengths for early traffic opening.

ANALISIS TINGKAT KEBISINGAN DAN UPAYA PENGENDALIAN PENYAKIT AKIBAT KERJA DI AREA MINING PT. XYZ, SUMBAWA BARAT, NUSA TENGGARA BARAT

Aspek K3 berorientasi menciptakan lingkungan kerja yang aman, nyaman, dan sehat bagi pekerja. Industri pertambangan memiliki tingkat resiko cukup tinggi khususnya terkait kebisingan di tempat kerja yang berasal dari intensitas suara tinggi pada aktivitas penambangan, peledakan, alat, mesin, dan perbengkelan. Penelitian dilakukan di area penambangan PT. XYZ, salah satu perusahaan tambang terbuka yang berlokasi di Sumbawa Barat, Nusa Tenggara Barat dengan pengukuran kebisingan dilakukan dengan metode personal sampling dilakukan menggunakan peralatan Edge 5, dan mengetahui upaya pengendalian kebisingan dengan cara observasi dan wawancara mendalam dengan metode deskriptif kualitatif. Hasil penelitian didapatkan pembagian 12 Similar Exposure Group (SEG) di area mining PT.XYZ dengan hasil pengukuran kebisingan personal menunjukkan rentang 81.1-87 dB dengan SEG tertinggi di area Mine Batch Plant dan terendah di SEG Mine Drill Sampler. PT. XYZ telah melakukan upaya pengendalian kebisingan dengan prinsip hirarki kontrol yaitu eliminasi, substitusi, rekayasa teknik, administrasi, dan alat pelindung diri.Keywords: Kebisingan, K3, Mining, Similar Exposure Group, Hirarki Kontrol ABSTRACTOccupational Health and Safety aspects create a safe and healthy work environment for workers. The mining industry has a high level of risk, especially related to workplaces originating from high noise intensity in mining, explosions, tools, and machinery and workshop activities. The research was conducted in the mining area of PT. XYZ, a company located in West Sumbawa, West Nusa Tenggara Province, was carried out using a private sampling method using Edge 5 equipment, and knowing control efforts by observation and in-depth qualitative descriptive methods. The results showed that there were 12 Similar Exposure Groups (SEG) in the mining area of PT. XYZ. Personal noise dosimetry measurement results showing a range of 81.1-87 dB with the highest SEG in the Mine Batch Plant area and the lowest in the SEG Mine Drill Sampler. PT. XYZ has carried out control efforts with the principles of the control hierarchy, namely elimination, substitution, engineering, administration, and personal protective equipment.Keywords: Noise, OHS, Mining, Similar Exposure Groups, Hierarchy Control

Optimization of Multiproduct Batch Plant Design for Protein Production Using Gradient Boosting Algorithms

This work deals with the problem of modeling and prediction of compressive strength of concrete structure in multiproduct batch plant design of protein production found in a chemical engineering process with uncertain demand. Modeling the strength of concrete for this process is very complex. However, it can be solved by minimizing the investment cost. Therefore, the aim of this work is to minimize the investment cost and find out the number and size of parallel equipment units in each stage. For this purpose, it is proposed to solve the problem by using gradient boosting algorithms, could be interpreted as an optimization algorithm on a suitable cost function. Which take into account, the uncertainty on the demand using gaussian process modeling. The results about number and size of equipments investment cost, production time, process time and Idle times in plant obtained by gradient boosting algorithms are the best. This methodology can help the decision makers and constitutes a very promising framework for finding a set of “good solutions”.

Modelling and Prediction of Compressive Strength of Hydraulic Concrete Structure in Multiproduct Batch Plant Design for Protein Production using Extreme Gradient Boosting Regressor with Grid Search support

This work deals with the problem of modeling and prediction of compressive strength of concrete structure in multiproduct batch plant design of protein production found in a chemical engineering process with uncertain demand. Modeling the strength of concrete for this process is very complex. However, it can be solved by minimizing the investment cost. Therefore, the aim of this work is to minimize the investment cost and find out the number and size of parallel equipment units in each stage. For this purpose, it is proposed to solve the problem by using extreme gradient boosting regressor with grid search support (XGBoost), could be interpreted as an optimization algorithm on a suitable cost function, which take into account, the uncertainty on the demand using gaussian process modeling. The results about number and size of equipment’s, investment cost, production time, process time and idle times in plant obtained by light gradient boosted trees regressor are the best. This methodology can help the decision makers and constitutes a very promising framework for finding a set of “good solutions”.

Utilization of SCC Technology for Large Placements in New Nuclear Construction: A Study On SCC Stability and Constructability

This paper discusses the use of Self Consolidating Concrete (SCC), in a large scale placement during new nuclear plant construction. SCC has provided cost and labor savings and construction process improvements. Use of SCC has been effective in schedule acceleration by reducing placement durations and early curing termination with rapid strength gain. Self-consolidating properties were particularly of value at placements of poor access as internal vibrators were not effective and large surface area made form vibrators ineffective beyond the perimeter. This paper provides a discussion of technical challenges encountered in development of a properly functioning SCC mixture, and testing performed to overcome these challenges. The paper discusses the engineering considerations and laboratory and field trials preparing for a 3950 cubic meter placement for the basemat of a nuclear plant. The placement was anticipated to take 35 hours at 110 m3/hour batch plant output. Overview of mix design specifications and mix development is provided. The mixture satisfied the laboratory test parameters including SCC tests; stability and column segregation. However, the mixture had to undergo rounds of constructability testing beyond laboratory development prior to the large placement. The placement was completed successfully in 35 hours over multiple shifts.

THE INFLUENCE OF DISTILLATION METHODS ON THE FLAVOR PROFILE AND QUALITY INDICES OF WINE BRANDIES

The article examines the geographical area delimited for the production of the Divine and the specific characteristics and physical-geographical conditions of the Călărași vineyard through the prism of different methods of distillation and production of wine distillates. Technological regimes for distilling wine raw materials and organoleptic and physico-chemical indices such as: alcohol content, optical density, pH, aldehyde content, higher alcohol content and volatile acid content are scientifically argued. The quality indicators were determined for both wines and distillates obtained at the 'Charente' batch plant and the 'VAND-M-0' plant. The impact of the distillation method on the quality and production process of the wine distillate is evaluated.