scholarly journals Roller Compacted Concrete – Best Practice Of Lithuania

2021 ◽  
Vol 1202 (1) ◽  
pp. 012010
Author(s):  
Audrius Vaitkus ◽  
Rafal Mickevič ◽  
Ovidijus Šernas

Abstract In these days constantly being looking for solution to reduce construction costs, the amount of materials used and the negative impact on the environment. Designing pavement structures with top layer of traditional concrete, the structures become very massive. An alternative to traditional concrete is roller-compacted concrete, the concrete with significantly larger fine aggregates which lead concrete mix to be non-slip. The roller-compacted mix can also achieve high concrete density and consolidation by rolling. Roller-compacted concrete is also an economical and fast-construction alternative for many pavement applications. In Lithuania, roller-compacted concrete as the top layer is an innovation and first application of it was few years ago. However, in recent years application of roller-compacted concrete increased in industrial areas and low-volume rural roads. The best practice of application of roller-compacted concrete was in Klaipeda Free Economic Zone, where roller-compacted concrete was used as the top layer of industrial area for heavy load traffic. Fresh roller-compacted concrete workability decreases with time, to reduce transportation time and avoid excessive moisture loss, which can cause problems in placement of roller-compacted concrete, mobile concrete batching plant used. Mobile concrete batching plant was located near construction site.

2020 ◽  
Vol 12 (0) ◽  
pp. 1-5
Author(s):  
Rafal Mickevič ◽  
Audrius Vaitkus

In these days constantly being looking for solution to reduce construction costs, the amount of materials used and the negative impact on the environment. Designing pavement structures with top layer of traditional concrete, the structures become very massive because of variation of concrete thickness from 20 cm to 29 cm according to the standard structures with concrete which are given in KPT SDK 19. An alternative to traditional concrete is roller-compacted concrete, the concrete with significantly larger fine aggregates which lead concrete mix to be non-slip. The roller-compacted mix can also achieve high concrete density and consolidation by rolling. The experimental studies were performed according to the guidelines of the “Guide for rollercompacted concrete pavements” and the automated StreetPave program. Twelve different variants of the pavement structure were used in the calculations, in which the main variables were: the modulus of deformation (Ev2), the thickness of stabilized layer (CTS) and the modulus of elasticity (E). Calculations were also performed for two scenarios, assuming that the amount of cracks appearing on the surface of the top layer after the design period would be 5% and 10%.


Author(s):  
Ali Mardani ◽  
Sultan Husein Bayqra ◽  
Süleyman Özen ◽  
Zia Ahmad Faqiri ◽  
Kambiz Ramyar

2020 ◽  
Vol 3 (2) ◽  
pp. 41-52
Author(s):  
Gustavo Moreno López

We are what they eat and what we listen as well. Concerning this idea, it is essential to mention that reggaeton is one of the most consumed genres in many countries. Furthermore, to the extent that people regularly listen to music on platforms and express to like reggaeton in recent years, they may want to know more about what they are consuming. However, in the related literature, there is evidence of a negative impact on the women’s image and heavy load of sexual content (Gallucci, 2008; Noriega, 2014; Ramírez, 2012). Therefore, the present article analyses the discourse of “no me conoce” by J. Balvin, Bad Bunny, and Jhay Cortez. The lyrics and images were analyzed using systemic functional linguistics (Halliday & Matthiessen, 2003) and visual semiotics (Machin, 2010). The findings suggest that this genre contributes negatively to educational stances, such as writing proficiency, vocabulary range, and reading comprehension.


2017 ◽  
Vol 1 (2) ◽  
pp. 067
Author(s):  
Abi Pratiwa Siregar ◽  
Jamhari Jamhari ◽  
Lestari Rahayu Waluyati

This study assessed the performance of 32 village unit co-operatives (KUD) in Yogyakarta Special Region during 2011 to 2012. The efficiency level of the KUD were evaluated by employing the data envelopment analysis and multiple regression analysis using panel data to determine the factors affecting efficiency level. Efficiency analysis was decomposed into three dimensions to explore possible sources of inefficiency. According to Marwa and Aziakpono (2016), the first dimension was technical efficiency, which explored the overall effectiveness of transforming the productive inputs into desired outputs compared to the data-driven frontier of best practice. The second dimension was pure technical efficiency, which captured managerial efficiency in the intermediation process. The third dimension was scale efficiency, which explored whether KUD were operating in an optimal scale of operation or not. The results found that the average scores are 64%, 92%, and 68% for technical, pure technical, and scale efficiency respectively in 2011, while in 2012 the average scores are 57%, 94%, and 60% for technical, pure technical, and scale efficiency. Factors having significantly positive impact on several measures of efficiency are incentive and dummy variables (agriculture inputs and hand tractor). Accounts receivable only has positive relationship to pure technical efficiency. On the other hand, rice milling unit and electricity services have negative impact with several measures of efficiency.


2018 ◽  
Vol 68 (332) ◽  
pp. 168 ◽  
Author(s):  
P. Saiz-Martínez ◽  
D. Ferrández-Vega ◽  
C. Morón-Fernández ◽  
A. Payán de Tejada-Alonso

Construction and demolition waste can be used as a substitution of natural aggregate in mortar and concrete elaboration. A poorer quality of recycled aggregates generally has negative impact on mortar properties. Shrinkage is one of the properties that experiences worse outcome due to the higher absorption of recycled aggregates. This research evaluates the potential shrinkage of mortars elaborated with recycled concrete aggregates both with and without fibres addition, as well as the relation between moisture loss and shrinkage caused by mortar drying process using a capacitive sensor of the authors’ own design. Two different mortar dosages 1:3 and 1:4 and three fiber types: polypropylene fiber, fiberglass and steel fiber, in different proportions were used. Obtained results show that the use of polypropylene fiber improves the recycled mortars performance against shrinkage in 0.2%. Moreover, a clear relation between dry shrinkage and moisture loss was observed.


2021 ◽  
Vol 9 (07) ◽  
pp. 112-118
Author(s):  
Dra. Flor Calvanapon Alva ◽  
◽  
Mg. Karina Cardenas Rodriguez ◽  
Silvia Cespedes Esquivel ◽  
Roxana Lujan Rodriguez ◽  
...  

In order to determine the impact of the construction budget on the construction costs of the Santa Maria Corporation SAC-2020, an applied research was carried out, qualitative approach, non-experimental design and correlational scope, the sample are works executed in times of health crisis the school buildings No. 81540 San Francisco de Asis and No. 80638 Americo Aguilar Celis, in the province of Viru. Thestudytechniqueused was documentary analysis and the instrument was a record card. The data obtained were processed to evaluate the incidence of the variables by means of statistical tables where it was found that 4.29% additional materials were used for the first work and 4.33% additional for the second, with respect to the budget in the case of direct general expenses, 18.75% and 23.33% respectively, additional to the estimate. It is concluded that the construction budget has a negative impact on the construction costs of Corporacion Santa Maria SAC-2020 in times of sanitary crisis, observing relevant variations between the estimated and executed costs, not obtaining the expected profit margin noting that in the case of the first project the profit margin is only 10% of the estimate and in the second projectitis 0%.


2016 ◽  
Vol 11 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Maria de Lurdes Antunes ◽  
Vânia Marecos ◽  
José Neves ◽  
João Morgado

The construction and maintenance of a road network involve the expenditure of large budgets. In order to optimize the investments in road infrastructures, designers and decision makers should have the instruments to make the most suitable decision of paving solutions for each particular situation. The life-cycle assessment is an important tool of different road pavement solutions with this purpose. This paper presents a study concerning the life-cycle cost analysis of different flexible and semi-rigid paving alternatives, with the objective to contribute for a better support in the decision process when designing new pavement structures. The analysis was carried out using data on construction costs of certain typical pavement structures and taking into consideration appropriate performance models for each type of structure being selected. The models were calibrated using results from long term performance studies across Europe and the maintenance strategies considered have taken into account the current practice also found in the European context. Besides the life-cycle administration costs, the proposed methodology also deals with user and environmental costs through its inclusion in the decision process using multi-criteria analysis. It was demonstrated that this methodology could be a simple and useful tool in order to achieve the most adequate paving solutions of a road network, in terms of construction and maintenance activities, based simultaneously on technical, economic and environmental criteria.


2021 ◽  
pp. 46-51
Author(s):  
V. YA. ZHARNITSKIY ◽  
◽  
A. P. SMIRNOV

Identified in the process of analyzing the operation of the structure, in the conditions of its operation, allow to assess the actual reserves of the bearing capacity of the structure and take effective measures to restore the operational parameters. The main criteria influencing the choice of mathematical models of materials for structures and elements of soil dams are more consistent with the model of the equation of state connecting the components of stress and strain tensors, as well as the rate of their change, which are obtained and tested for numerical calculations and have a full set of constants for materials used in the calculations of earth dams, the choice of their structures (concrete,reinforced concrete, soils, etc.). Reliable operation of soil dams is possible only if all proper conditions are met. The causes of dam accidents and their damage must be known not only to eliminate errors at the design and construction stages, but also during their operation. In order to exclude the negative impact of operational factors on the safety of soil HTS, it is necessary not only to strictly observe the rules of technical operation and take measures to exclude the possibility of an emergency situation during technological operations at facilities, but also to have methods for predictive justification of the restoration of strength and operational indicators of structures and elements of soil dams.


Author(s):  
Rokhmah Hergiyani ◽  
Y. S. Darmanto ◽  
Lukita Purnamayati

Kulit ikan merupakan limbah perikanan yang dapat memberikan dampak negatif pada lingkungan. Salah satu cara untuk menanggulangi limbah tersebut adalah dengan proses penyamakan kulit. Penyamakan kulit adalah rangkaian proses yang sangat kompleks terjadi banyak perubahan fisik dan kimia di satu sisi, bagian yang tidak berguna dihilangkan dari kulit mentah untuk mendapatkan serat kolagen murni dan membuka struktur serat kolagen. Proses penyamakan yang tidak baik mengakibatkan kulit menjadi rusak, lemas, dan kebusukan, sehingga penanganannya dapat dengan cara menambah bahan penyamak untuk menguatkan dan menghindari kebusukan. Bahan penyamak yang digunakan yaitu zirconium. Tujuan penelitian ini adalah untuk mengetahui pengaruh penyamakan zirkonium terhadap uji kekuatan tarik, uji kekuatan sobek, uji kemuluran dan uji suhu kerut pada berbagai jenis ikan. Bahan baku yang digunakan adalah kulit ikan nila, kakap dan bandeng. Metode penelitian yang digunakan adalah experimental laboratories menggunakan Rancangan Acak Lengkap (RAL) dengan tiga kali ulangan dan  menggunakan analisa ragam ANOVA. Hasil uji menunjukan penggunaan zirkonium 7,5% terhadap kulit ikan nila, kakap, dan bandeng berpengaruh nyata (p<0,05) pada kekuatan tarik, kekuatan sobek, kemuluran dan suhu kerut pada karakteristik penyamakan. Penggunaan bahan penyamak zirkonium 7,5% terbaik dihasilkan oleh kulit ikan kakap pada uji kekuatan tarik 1675,84 N/cm2, kekuatan sobek 163,92 N/cm2 dan uji suhu kerut 103,45˚C sedangkan kemuluran untuk hasil terbaik pada kulit bandeng sebesar 28,74%, jadi setiap ikan mempunyai ciri kulit tersendiri pada setiap parameter uji. The skin of the fish waste is a fishery that can give a negative impact on the environment. One way of tackling the waste is by the process of tanning leather. Tanning is a very complex processes occur many chemical and physical changes on the one hand, the useless removed from rawhide to get pure collagen fibers and the open structure of the collagen fibers. The process of tanning is not a good result in the skin becomes broken, buckled, and corruption, so that responses can be with how to add ingredients to strengthen Tanner and avoid corruption. On the research of materials used i.e. Tanners used are zirconium.. The purpose of this research is to know the influence of zirconium tanning against test tensile strength, tear strength test, test and test temperature wrinkle elongation on various types of fish. The raw material used is leather fish tilapia, milkfish and snapper. Research methods used are experimental laboratories using Complete Random Design (RAL) with three-time repeats and a range of analysis using ANOVA. Test results showed the use of zirconium 7.5% against the skin of the fish, snapper, tilapia and milkfish influential real (p < 0.05) on the tensile strength, tear strength, elongation and wrinkle on temperature characteristics of tanning. The use of zirconium Tanner 7.5% best produced by skin test on a snapper 1675.84 tensile strength N/cm2, the strength of RIP 163.92 N/cm2 and test the temperature of the wrinkle 103,45 ˚ C while elongation for the best results on the skin of the banding of 28.74%, so each fish has its own skin characteristics on each test parameter.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1069 ◽  
Author(s):  
Fahd Saeed Alakbari ◽  
Mysara Eissa Mohyaldinn ◽  
Ali Samer Muhsan ◽  
Nurul Hasan ◽  
Tarek Ganat

The chemical sand consolidation methods involve pumping of chemical materials, like furan resin and silicate non-polymer materials into unconsolidated sandstone formations, in order to minimize sand production with the fluids produced from the hydrocarbon reservoirs. The injected chemical material, predominantly polymer, bonds sand grains together, lead to higher compressive strength of the rock. Hence, less amounts of sand particles are entrained in the produced fluids. However, the effect of this bonding may impose a negative impact on the formation productivity due to the reduction in rock permeability. Therefore, it is always essential to select a chemical material that can provide the highest possible compressive strength with minimum permeability reduction. This review article discusses the chemical materials used for sand consolidation and presents an in-depth evaluation between these materials to serve as a screening tool that can assist in the selection of chemical sand consolidation material, which in turn, helps optimize the sand control performance. The review paper also highlights the progressive improvement in chemical sand consolidation methods, from using different types of polymers to nanoparticles utilization, as well as track the impact of the improvement in sand consolidation efficiency and production performance. Based on this review, the nanoparticle-related martials are highly recommended to be applied as sand consolidation agents, due to their ability to generate acceptable rock strength with insignificant reduction in rock permeability.


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