scholarly journals Experimental Study on Dynamic Mechanical Properties of Coal Gangue Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Zhishu Yao ◽  
Yu Fang ◽  
Weihao Kong ◽  
Xianwen Huang ◽  
Xuesong Wang

In order to study the static and dynamic mechanical characteristics of the coal gangue concrete used in the mine support structure, the compressive strength test, the drop weight impact test, and the Split Hopkinson Pressure Bar (SHPB) test were conducted. The compressive strength, initial and final impacting energy, dynamic strength, and failure characteristic of concrete were obtained of the concrete single-doped with coal gangue coarse aggregate, single-doped with coal gangue fine aggregate, and codoped with coal gangue coarse and fine aggregates. The results show that (1) it is feasible that employing coal gangue to replace natural coarse and fine aggregates in concrete can prepare C30 and C40 concrete; (2) the addition of coal gangue fine aggregate has a positive effect on the impact energy of the initial and final cracks of concrete, while the addition of coal gangue coarse aggregate has a negative effect on it; (3) compared with the static strength, the dynamic strength of concrete is improved no matter whether coal gangue is added to concrete; (4) the incorporation of coal gangue coarse aggregate will make the concrete shear surface smooth; (5) at the given impacting pressure, the concrete with coal gangue coarse aggregate has greater particle breakage and those with coal gangue fine aggregate has less. The research of this study can be a reference for the application of gangue concrete in mine support structures.

2020 ◽  
Vol 991 ◽  
pp. 62-69
Author(s):  
Sallehan Ismail ◽  
Mohamad Asri Abd Hamid ◽  
Zaiton Yaacob

This study aims to investigate the dynamic behavior of recycled mortar under impact loading using a split Hopkinson pressure bar (SHPB). Several mortar mixtures were produced by adding various fine recycled aggregates (FRA) to the mixture in replacement percentages of 0%, 25%, 50%, 75%, and 100% of the natural fine aggregate (NFA). The effects of strain rate on compressive strength and specific energy absorption were obtained. Results show that the dynamic compressive strength and specific energy absorption of recycled mortar are highly strain rate dependent; specifically, they increase nearly linearly with the increase in peak strain rate. However, the compressive strength and specific energy absorption of recycled mortar are generally lower than those of NFA mortar (reference samples) under similar high strain rates. The findings of this research can help researchers and construction practitioners to ascertain the appropriate mix design procedure to optimize the impact strength properties of recycled mortar for protective structural application.


2019 ◽  
Vol 801 ◽  
pp. 391-396
Author(s):  
Janardhan Prashanth ◽  
Harish Narayana ◽  
Ramji Prasad

In this paper comparative study on the compressive strength and permeability of pervious concrete with and without fine aggregate is done. Sand and LLDPE (Linear low density polythene) with varying percentages are used as fine aggregates. Sand is added in percentages of 5%, 10% and 15% of the coarse aggregate in all the mixes. LLDPE powder is added in the percentage of 5%, 10% and 15% of the coarse aggregate in all the mixes. With the addition of fine aggregate the compressive strength of the pervious concrete increases but permeability reduces. The results show that the pervious concrete with LLDPE powder there is a considerable increase in compressive strength as compared to no-fines mix and mix with sand as fine aggregate. The study recommends the use of eco-friendly pervious concrete with LLDPE powder as an alternative to the existing pavements with low volume traffic.


2016 ◽  
Vol 847 ◽  
pp. 437-444 ◽  
Author(s):  
Ying Liang Tian ◽  
Wen Cai Liu ◽  
Su Ping Cui ◽  
Shi Bing Sun ◽  
Yi Wang ◽  
...  

In recent decades, high-tech electrical equipment has drastically proliferated instead of Cathode Ray Tube (CRT), making CRT funnel glass potential hazardous solid waste. Due to a relatively high level of lead, CRT funnel glass could be used as a potential material for the production of anti-radioactive concrete. In our study the CRT funnel glass , which was separated as aggregate in the concrete, was reduced to 4.75-25 mm (coarse aggregates) and less 4.75 mm (fine aggregates) in the production of anti-radioactive concrete. Mixes containing 0%, 20%, 40% , 60%, 80% and 100% (volume percentage) of CRT funnel glass to replace fine aggregate and coarse aggregate (respectively or simultaneously)) were prepared. The influence of the size, shape and replacement percentage of aggregates on workability, compressive strength and radiation shielding performance were determined. It was found that the replacement of natural aggregate with recycled CRT glass considerably improved the slump and radiation shielding performance but reduced compressive strength. The optimum percentage of waste funnel glass used as fine aggregate and coarse aggregate was 40%. The results clearly showed that the CRT funnel glass performed a significant enhancement in radiation shielding properties.


2021 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Agung Prayogi

Abstract Concrete is the most widely used material throughout the world and innovations continue to be carried out to produce efficient development. Shell charcoal ash and rice husk ash are industrial by-products which have the potential to replace sand for concrete mix, especially in Indragiri Hilir. The research with the title "Effect of Mixture of Rice Husk Ash and Shell Ash Ashes as Substitute for Some Fine Aggregates Against Concrete Compressive Strength" aims to prove the effect of a mixture of shell charcoal ash and husk ash to replace some of the sand to produce maximum compressive strength. Concrete is a mixture of Portland cement, fine aggregate, coarse aggregate, and water. This research uses 5 variations of the mixture to the weight of sand, BSA 0 without a substitute mixture, BSA 1 with a mixture of 5% husk ash and 10% shell charcoal, BSA 2 with a mixture of 5% husk ash and 15% charcoal ash, BSA 3 with a mixture of 5% husk ash and 18% charcoal, BSA 4 with a mixture of 10% husk and 10% charcoal, and BSA 5 with a mixture of 13% husk ash and 10% charcoal ash. SNI method is used for the Job Mix Formula (JMF) mixture in this research. The results of the average compressive strength of concrete at 28 days for JMF of 21.05 MPa, BSA 1 of 23.68 MPa, BSA 2 of 22.23 MPa, BSA 3 of 14.39 MPa, BSA 4 of 13.34 MPa , and BSA 5 of 20.14 MPa. The conclusion drawn from the results of the BSA 1 research with a mixture of 5% husk ash and 15% charcoal ash produced the highest average compressive strength of 23.68 MPa. Abstrak Beton merupakan material paling banyak digunakan diseluruh dunia dan terus dilakukan inovasi untuk menghasilkan pembangunan yang efisien. Abu arang tempurung dan abu sekam padi merupakan hasil sampingan industri yang berpotensi sebagai pengganti pasir untuk campuran beton, khususnya di Indragiri Hilir. Penelitian dengan judul “Pengaruh Campuran Abu Sekam Padi dan Abu Arang Tempurung Sebagai Pengganti Sebagian Agregat Halus Terhadap Kuat Tekan Beton” ini bertujuan membuktikan adanya pengaruh campuran abu arang tempurung dan abu sekam untuk mengganti sebagian pasir hingga menghasilkan kuat tekan maksimum. Beton adalah campuran antara semen portland, agregat halus, agregat kasar, dan air. Penelitian ini menggunakan 5 variasi campuran terhadap berat pasir, BSA 0 tanpa campuran pengganti, BSA 1 dengan campuran 5 % abu sekam dan 10% arang tempurung, BSA 2 dengan campuran 5% abu sekam dan 15% abu arang, BSA 3 dengan campuran 5% abu sekam dan 18% arang, BSA 4 dengan campuran 10% sekam dan 10% arang, dan BSA 5 dengan campuran 13% abu sekam dan 10% abu arang. Metode SNI digunakan untuk campuran Job Mix Formula (JMF)  pada penelitian ini. Hasil rata-rata kuat tekan beton pada umur 28 hari untuk JMF sebesar 21,05 MPa, BSA 1 sebesar 23,68 MPa, BSA 2 sebesar 22,23 MPa, BSA 3 sebesar 14,39 MPa, BSA 4 sebesar 13,34 MPa, dan BSA 5 Sebesar 20,14 MPa. Ditarik kesimpulan dari hasil penelitian BSA 1 dengan campuran 5% abu sekam dan 15% abu arang menghasilkan rata-rata kuat tekan tertinggi yaitu sebesar 23,68 MPa.  


Author(s):  
Suwendy Arifin Et.al

Pervious concrete or non-fine concrete is a simple form of lightweight concrete made by eliminating the use of fine aggregates. As a result of not using fine aggregate in pervious concrete, then created a cavity filled with air and water can be passed. This cavity resulted in reduced density of the concrete as well as the reduced amount of area that needs to be covered by cement paste, thereby reducing the compressive strength. To increase the compressive strength of pervious concrete, in this study will utilize waste material. The waste material is the cocnut shell ash and coconut shell to strengthen the coarse aggregate bonds, so it is expected to increase the compressive strength along with the increase in permeability. Thus, in this study will replace part of the coarse aggregate with coconut shell with percentage 0%, 2,5%, 5%, 7,5%, 10% and partially replace cement with coconut shell ash with percentage 0%, 2,5%, 5%, 7,5%


Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 81
Author(s):  
Fernando A. N. Silva ◽  
João M. P. Q. Delgado ◽  
António C. Azevedo ◽  
António G. B. Lima ◽  
Castorina S. Vieira

This work aims to study the influence of using construction and demolition waste in the replacement of coarse and fine aggregate to produce recycled aggregate concrete (RAC). A moderate compressive strength concrete made with usual fine and coarse aggregate was used as a benchmark material. Compressive and split tensile tests were performed using 120 cylindrical concrete specimens with 150 mm diameter and 300 mm length. Four-point flexural tests in reinforced beams made with conventional concrete and RAC were performed. The results obtained showed that the use of recycled fine aggregates, in both percentages of substitution investigated—50% and 100%— did not generate any deleterious influence on the values of compressive strength and split tensile strength of the RACs produced. Tin fact, the mechanical strengths of RACs produced with recycled fine aggregate were equal or higher than those from the reference concrete. The same behavior was not observed, however, when the recycled coarse aggregate was used. For this case, decreases in concrete mechanical strengths were observed, especially in compressive strength, with values around 35% lower when compared to the reference concrete. Tensile mechanical tests results confirmed the excellent behavior of all RACs made with replacement of usual fine aggregates by recycled. Bending tests performed in reinforced RAC beams had as objective to evaluate the deformation profile of the beams. The obtained results showed that RAC beams with full replacement of usual fine aggregate by the recycled aggregates have presented little changes in the global behavior, an aspect that encourages its use.


2016 ◽  
Vol 858 ◽  
pp. 86-90 ◽  
Author(s):  
Zhen Ming Chen ◽  
Yue Xiao Li ◽  
Zheng Zhang

Based on the SHPB (Split Hopkinson Pressure Bar), the dynamic mechanical properties of the granite in the borehole have been tested separately. The data shows that the impact dynamic strength increases as the precompression stress increases and can reach its maximum when the precompression stress is about 50% of the static tension strength. Meanwhile, the coupled static and dynamic strength increases as well, and it could reach about three times of the static precompression stress and one and half times of the dynamic strength respectively. Also, the failure model of the coupled static and dynamic loading is tension failure, which is the same as the static tension and conventional dynamic loading test.


2021 ◽  
Vol 2 (1) ◽  
pp. 46-54
Author(s):  
Neti Rahmawati ◽  
Irwan Lakawa ◽  
Sulaiman Sulaiman

Concrete is one of the most widely used building materials today interms of physical construction. Concrete is made from a mixture offine, coarse aggregate, cement, and water with a certain ratio, aswell as materials that are usually added to the concrete mixtureduring or during mixing, to changing the properties of concrete tomake it more suitable in certain jobs and more economical, can alsobe added with certain other mixed materials as needed if deemednecessary. Seashells can be used to mix concrete. This study aims todetermine whether the addition of shells aggregate shells in aconcrete mixture can affect the mechanical properties of concrete.The specimens used are in the form of cubes with a size of 15cm x 15cm x 15 cm, consisting of additional concrete coarse and fineaggregate with shell substitution percentage of 0%, 15%, 20% with atotal sample of 45, with the planned concrete quality of K225. Theuse of sea shells in increasing the compressive strength of concrete isbetter used as fine aggregate than coarse aggregate. The use of seashells as a substitute for fine aggregates achieves maximum resultsat 20% composition.


2019 ◽  
Vol 6 (2) ◽  
pp. 145
Author(s):  
Budiman Budiman

Concrete waste from building construction can cause problems for the environment [1]. The use of fine aggregates from concrete waste can be a solution. The purpose of this study is to determine the value of aggregate characteristics and the value of concrete compressive strength from the utilization of concrete waste as substitution fine aggregate use the DOE (department of environment) method and referring to standards SNI. This study used 50% and 60% waste mortal substitution on sand. The results showed that the characteristics of fine aggregate and coarse aggregate met the characteristic requirements for fineness modulus sand of 2.65 (Zone 2) while the aggregate was roughly 6.44 (Zone 3). The value of compressive strength with 50% and 60% concrete waste substitution each obtained the value of characteristic compressive strength of 57.24 kg / cm² and 101.03 kg / cm². The value of using mortar waste as fine aggregate substitution gives a positive value to the quality of concrete. This is evidenced increase in the value of 14.89% in concrete waste substitution 60%.


2018 ◽  
Vol 3 (1) ◽  
pp. 55
Author(s):  
Suhendra Suhendra

Aggregate quality is very influential on the strength of the resulting concrete. Both coarse and fine aggregates have various characteristics identified from laboratory test results. This study aims to examine the use of various aggregates for a quality of concrete. The coarse aggregate and the fine aggregate used are obtained from the nearest location to the work to be performed. The quality of the concrete reviewed is K-125, K-175 and K-225. The coarse aggregates used are 1-2 size (in cm), 2-3 size (in cm) crushed aggregate and coral. The fine aggregates used for each of the coarse aggregates are also different. The results showed that the coral aggregate did not meet the gradations of concrete aggregate. While the fine aggregate does not meet the gradation of concrete aggregate for the three types used. The concrete compressive strength test results show the use of coarse aggregates of 2-3 size of crushed and coarse aggregate of corals giving the average compressive strength value required for all planned concrete strength. While concrete using coarse aggregates of rocks of size 1-2 only meet the specified compressive strength, but does not meet the required compressive strength.Key words: Aggregates, concrete, compressive strength


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