scholarly journals Axial Compressive Behavior of Geopolymer Recycled Lump Concrete

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 533 ◽  
Author(s):  
Haiyan Zhang ◽  
Jiancheng Liu ◽  
Bo Wu ◽  
Zhijian Zhang
Keyword(s):  
Compressive Strength ◽  
Geopolymer Concrete ◽  
Strengthening Effect ◽  
Test Results ◽  
Compressive Behavior ◽  
Replacement Ratio ◽  
Experimental Conditions ◽  
Cement Production ◽  
Modified Method ◽  
Measured Strength

To reduce the environmental pollution from cement production and the damage to natural resources from aggregate mining in the concrete industry, a relatively new concrete, termed geopolymer recycled lump concrete (GRLC), which uses geopolymer as the binding material to replace traditional cement and uses large demolished concrete lumps (DCLs) to partly replace concrete, is prepared in this study. Cubic and cylindrical GRLC specimens containing fresh geopolymer concrete and DCLs were tested under axial compression with various parameters, including the compressive strength levels of both fresh geopolymer concrete and DCLs, and the replacement ratio of DCLs. The compressive behavior of the GRLC specimens was compared with traditional cement recycled lump concrete (CRLC) specimens, with test results showing that GRLC specimens possess higher compressive strength than CRLC specimens under the same experimental conditions, which is due to the strengthening effect that fresh geopolymer concrete has on the DCLs. From the scanning electron microscope pattern of the GRLC specimen, it is found that the geopolymer bonds well with the old mortar attached to DCLs. As the replacement ratio increases from 0% to 33%, the elastic modulus of GRLC increases by 5%–11% but Poisson’s ratio remains almost constant (in the 0.16–0.17 range). Based on the measured strength and the predicted results, which coincide with one another well, a modified method for predicting the compressive strength of GRLC cubic and cylindrical specimens is proposed.

scholarly journals Compressive Strength, Chloride Ion Penetrability, and Carbonation Characteristic of Concrete with Mixed Slag Aggregate

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 940
Author(s):  
Se-Jin Choi ◽  
Young-Uk Kim ◽  
Tae-Gue Oh ◽  
Bong-Suk Cho
Keyword(s):  
Compressive Strength ◽  
Steel Slag ◽  
Chloride Ion ◽  
Fine Aggregate ◽  
Test Results ◽  
Replacement Ratio ◽  
Concrete Aggregates ◽  
The Social ◽  
Ferronickel Slag ◽  
Natural Aggregates

The shortage of natural aggregates has recently emerged as a serious problem owing to the tremendous growth of the concrete industry. Consequently, the social interest in identifying aggregate materials as alternatives to natural aggregates has increased. In South Korea’s growing steel industry, a large amount of steel slag is generated and discarded every year, thereby causing environmental pollution. In previous studies, steel slag, such as blast furnace slag (BFS), has been used as substitutes for concrete aggregates; however, few studies have been conducted on concrete containing both BFS and Ferronickel slag (FNS) as the fine aggregate. In this study, the compressive strength, chloride ion penetrability, and carbonation characteristic of concrete with both FNS and BFS were investigated. The mixed slag fine aggregate (MSFA) was used to replace 0, 25%, 50%, 75%, and 100% of the natural fine aggregate volume. From the test results, the highest compressive strength after 56 days was observed for the B/F100 sample. The 56 days chloride ion penetrability of the B/F75, and B/F100 samples with the MSFA contents of 75% and 100% were low level, approximately 34%, and 54% lower than that of the plain sample, respectively. In addition, the carbonation depth of the samples decreased with the increase in replacement ratio of MSFA.

scholarly journals STUDI PENDAHULUAN BATAS MAKSIMUM KADAR LUMPUR PADA AGREGAT BETON GEOPOLIMER

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Djedjen Achmad ◽  
Desi Supriyan
Keyword(s):  
Compressive Strength ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Cement Concrete ◽  
Flexural Tensile Strength ◽  
Binder Ratio ◽  
The Impact ◽  
Water Binder Ratio

ABSTRACTHas been researched the impact of mud in aggregate on geopolymer concrete with studies using the cement concrete as a reference. In this study both of concrete are mixed with a variation of mud of 0%, 0.75%, 3% and 5.75% of the combined aggregate weight. Compressive strength of cement concrete is designed with a target of 300 kg / cm2 and geopolymer concrete is made with water binder ratio (w/b) 0.25, Molarity 12 M, the ratio of sodium silicate and sodium hydroxide 1.5. At the age of 3, 7, 14 and 28 day tested of compressive strength, while the spliting test, flexural tensile strength, and modulus of elasticity are tested at 28 days. From the test results, the higher mud content in aggregate , the mechanical properties of the concrete are decreased. Based on testing of compressive strength in cement concrete at 28 days, with a 3% mud content (the content of the reference mud) turns of compressive strength decreased by 77.356%. Of the percentage reduction on the compressive strength of the cement concrete, can be compared to the mud content in geopolymer concrete at 2.04%. Thus the maximum mud on geopolymer concrete aggregate is, for coarse aggregate of 0.68% and a maximum mud content for fine aggregate was 3.4%.Key words : Mud, aggregate, concrete, cement, geopolimer, strengthABSTRAKTelah diteliti dampak kadar lumpur pada agregat untuk beton geopolimer dengan penelitian menggunakan benda uji beton semen sebagai acuan dan beton geopolimer. Dalam penelitian ini ke dua beton tersebut dicampur dengan lumpur gabungan agregat kasar dan agregat halus dengan variasi 0 %, 0.75 %, 3 % dan 5,75 % dari berat agregat gabungan. Beton semen dirancang dengan target kuat tekan 300 kg/cm2 dan beton geopolimer dibuat dengan campuran water binder ratio (w/b) 0.25, Molaritas 12 M, perbandingan sodium silikat dan sodium hidroksida 1.5. Pada umur 3, 7, 14 dan 28 hari dilakukan uji kuat tekan, sedangkan uji kuat tarik belah, uji kuat tarik lentur, dan modulus elastisitas dilakukan pada umur 28 hari. Dari hasil uji terlihat bahwa semakin tinggi kadar lumpur pada agregat, karakteristik mekanis kedua beton tersebut mengalami penurunan. Berdasarkan pengujian kuat tekan pada beton semen umur 28 hari, dengan kadar lumpur 3 % (kadar lumpur referensi) ternyata beton semen mengalami penurunan kuat tekan sebesar 77.356 %. Dari persentase penurunan kuat tekan beton semen tersebut, diplot pada grafik kuat tekan beton geopolimer maka persentase kadar lumpur gabungan yang mengalami penurunan 77.356 % adalah 2.04 %. Dengan demikian kadar lumpur maksimum pada agregat beton geopolimer adalah, untuk agregat kasar sebesar 0.68 % dan kadar lumpur maksimum untuk agregat halus adalah 3.4 %.Kata kunci : Lumpur, agregat, beton, semen, geopolimer, kekuatan

scholarly journals Compressive Strength of Fly Ash Based Geopolymer Concrete Addition with Fibers

2020 ◽  
pp. 57-61
Author(s):  
B Anitha Rani V Bhargavi,
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Material ◽  
Polypropylene Fibers ◽  
Geopolymer Concrete ◽  
Inorganic Polymers ◽  
Cement Production ◽  
Compressive Strength Test ◽  
New Generation ◽  
Day By Day

Concrete is the most widely used construction material all over the world. The quantity of the water plays an important role in the preparation of concrete. And the demand of concrete is increasing day by day and cement is used for satisfying the need of development of infrastructure facilities, 1 tonne cement production generates 1 tonne CO2, which adversely affect the environment. In order to reduce the use of OPC and CO2 generation, the new generation concrete has been developed such as Geopolymer concrete (GPC). Geopolymers are inorganic polymers and their chemical composition is similar to natural materials. Geopolymer binders are the alternatives in the development of acid resistant concrete i.e. durability of concrete. Geopolymer concrete is produced using Fly ash at 100% replacement to cement and binders like NaOH, Na2SiO3 to ignite the geopolymerisation. Many studies were carried out on properties of geopolymer concrete. This study focuses on enhancing the strength of geopolymer concrete by using fibers. 60% polyester and 40% polypropylene fibers are added to geopolymer concrete addition with Fly ash content. The trail mixes were casted with addition of fibers at different percentages like (0.20, 0.25, 0.30, 0.35, 0.40, 0.45 and 0.50 %). Then samples were air-cured for 28 days at ambient temperature. Compressive strength test is conducted on the samples after 3, 7 and 28 days. The optimum value is obtained at 0.40% addition of fibers when compared to nominal mix(GPC).

Compressive behavior of steel spiral confined engineered cementitious composites in circular columns

2020 ◽  
Vol 23 (14) ◽  
pp. 3075-3088
Author(s):  
Wei Hou ◽  
Guan Lin ◽  
Xiaomeng Li ◽  
Pandeng Zheng ◽  
Zixiong Guo
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Uniaxial Tensile ◽  
Cementitious Composites ◽  
Test Results ◽  
Cementitious Composite ◽  
Compression Tests ◽  
Compressive Behavior ◽  
Engineered Cementitious Composites ◽  
Engineered Cementitious Composite

Extensive research has been conducted on the uniaxial tensile and compressive behavior of engineered cementitious composites. Despite the high tensile ductility and high toughness of engineered cementitious composites, transverse steel reinforcement is still necessary for high-performance structural members made of engineered cementitious composites. However, very limited research has been concerned with the compressive behavior of steel-confined engineered cementitious composites. This article presents the results of axial compression tests on a series of circular engineered cementitious composite columns confined with steel spirals. The test variables included the engineered cementitious composite compressive strength, the spiral pitch, and the spiral yield stress. The test results show that steel-confined engineered cementitious composites in the test columns exhibited a very ductile behavior; the steel spiral confinement contributed effectively to the enhancement of both strength and ductility of engineered cementitious composites. The test results were then interpreted by comparing them with the predictions from some existing models. It was found that the existing models previously developed for confined concrete failed to predict the compressive strength of steel-confined engineered cementitious composites with sufficient accuracy. New fitting equations for the compressive properties of steel-confined engineered cementitious composites were then obtained on the basis of the test results of this study as well as those from an existing study.

scholarly journals An Experimental Investigation of the Stress-Strain Behaviour of Geopolymer Concrete

2018 ◽  
Vol 26 (2) ◽  
pp. 30-34 ◽  
Author(s):  
M. Venu ◽  
T. D. Gunneswara Rao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Modulus Of Elasticity ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Stress Strain ◽  
Curing Conditions ◽  
Strain Behaviour ◽  
Measured Stress

AbstractThis paper focuses on the mechanical properties and modulus of elasticity of fly ash and GGBS based geopolymer concrete. In this study an 8 molarity concentration of NaOH and alkaline liquid ratio in a ratio of 2.5 was used. This study includes the stress-strain behaviour along with the flexural strength, compressive strength and split tensile strengths for the GPC20, GPC40 and GPC60 grades. Tests were carried out on 150 mm × 150 mm × 150 mm cubes and 100 × 100 × 500 mm prisms and 150 × 300 mm cylindrical geopolymer concrete specimens. The test results not- ed the good mechanical properties and measured stress-strain relations of fly ash and GGBS based geopolymer concrete under ambient curing conditions. The elastic modulus was significantly varied with increases in the grade of the concrete. An equation was proposed to determine the modulus of elasticity based on the compressive strength of the geopolymer concrete.

scholarly journals PENGGUNAAN VARIASI UKURAN DIAMETER BUTIR MAKSIMUM AGREGAT KASAR TERHADAP KUAT TEKAN BETON

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Aiyub Aiyub
Keyword(s):  
Compressive Strength ◽  
Test Specimen ◽  
Coarse Aggregate ◽  
Test Results ◽  
Modified Method ◽  
Gravel Size ◽  
Compressive Strength Test ◽  
Compressive Strength Of Concrete ◽  
Cylindrical Test ◽  
Grain Diameter

This study aims to determine the use of variations in the size of the maximum grain diameter of coarse aggregate on compressive strength of concrete with fas 0.45 by cylindrical test specimen size 15 x 30 cm. Planning mix desing using a modified method of ACI with fas value of 0.45 and the value of the planned 75-100 mm slump. This study includes compressive strength performed at age 7 days and 28 days, treatment is normally carried out with care marinade soaked in the tub for 7 days and 28 days. Compressive strength test results obtained in the test specimen 7 days old premises gravel size is 20.50 Mpa 12.5 mm, 19 mm, 16.99 MPa, 16.76 MPa is 25 mm and 31.5 mm was 14.57 Mpa , while the age at 28 days was 30.51 MPa 12.5 mm, 19 mm, 24.86 MPa, 21.85 MPa is 25 mm and 31.5 mm was 21.66 Mpa. So the smaller the aggregate maximum compressive strength used was obtained by the higher and conversely the greater the maximum aggregate used dihasikan compressive strength lower. keywords: compressive strength, maximum grain diameter

Compressive behavior of small-diameter concrete-filled fiber-reinforced polymer tubes as internal reinforcements

2019 ◽  
Vol 23 (4) ◽  
pp. 713-732 ◽  
Author(s):  
Shu Fang ◽  
Li-Juan Li ◽  
Tao Jiang ◽  
Bing Fu
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Small Diameter ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Stress Strain ◽  
Reinforced Polymer ◽  
Polymer Tubes

Concrete infilled in a small-diameter fiber-reinforced polymer tube is strongly confined, thus having a high compressive strength and excellent deformability. Such a feature is exploited in the development of two types of high-performance hybrid members at Guangdong University of Technology, China, by incorporating small-diameter (30 to 60 mm) concrete-filled fiber-reinforced polymer tubes as internal reinforcements. Understanding the compressive behavior of small-diameter concrete-filled fiber-reinforced polymer tubes is essential to understanding the behavior of the proposed hybrid members and the development of their design approaches. This article therefore presents a systematic study on the axial compressive behavior of small-diameter concrete-filled fiber-reinforced polymer tubes with the test parameters being the thickness, diameter, and fiber type of fiber-reinforced polymer tubes and concrete strength. The test results show that the tested small-diameter concrete-filled fiber-reinforced polymer tubes have a compressive strength and an ultimate axial strain of up to 267 MPa and 10.3%, which are, respectively, about 6 and 34 times that of the corresponding unconfined specimens, demonstrating the great potential of small-diameter concrete-filled fiber-reinforced polymer tubes as internal reinforcements for use in high-performance hybrid members. The applicability of three widely accepted stress–strain models developed based on test results of fiber-reinforced polymer-confined concrete cylinders with a diameter of 150 mm or above is also examined. It is shown that the three models tend to predict a steeper second portion of stress–strain responses than the test results, revealing the need of a tailored stress–strain model for small-diameter concrete-filled fiber-reinforced polymer tubes.

“Recoil” Compressive Strength Test and the Evolution of Compressive Behavior in PAN-Based Carbon Fibers

1993 ◽  
Vol 305 ◽  
Author(s):  
Hao Jiang ◽  
S. Damodaran ◽  
A. S. Abhiraman ◽  
P. Desai ◽  
S. Kumar
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Carbon Fibers ◽  
Shear Failure ◽  
Relative Rate ◽  
Fracture Morphology ◽  
Test Results ◽  
Compressive Behavior ◽  
Compressive Properties ◽  
Compressive Strength Test

AbstractThe compressive properties of PAN-based carbon fibers were measured with the tensile recoil method. The recoil fracture morphology was also examined. In addition to the axial compression, flexure during recoil affects the test results. Compressive failure may be caused by shear failure and/or bending buckling of the microfibrils/fibrils. Study of the evolution of compressive and other mechanical properties discloses that, in general, the compressive strength bears a similar tendency to the tensile strength and torsion modulus up to the carbonization temperature of 1500 °C. However, the relative rate of evolution is different. To some extent, the bending buckling mechanism may relate to the structural units which govern the tensile strength.

Strength Enhancement of Bottom Ash-Based Concretes Using Metakaolin

2011 ◽  
Vol 695 ◽  
pp. 287-290
Author(s):  
J. M. Zhao ◽  
Z. X. Yang ◽  
Kyu Hong Hwang ◽  
M. C. Kim
Keyword(s):  
Compressive Strength ◽  
Fresh Concrete ◽  
Setting Time ◽  
Bottom Ash ◽  
Fine Aggregate ◽  
Test Results ◽  
Replacement Ratio ◽  
Natural Sand ◽  
Strength Enhancement ◽  
Compressive Strength Of Concrete

To replace bottom ash for natural sand completely, the mix proportions of bottom ash in concrete was adjusted according to tab density and replacement ratio of Metakaolin/Cement were established. And then testing for slump, setting time, and compressive strength was conducted. According to test results, the compressive strength of concrete using the bottom ash was lower than that of concrete using natural sand (BAO concrete). But by adjusting the amount of bottom ash in concrete according tab density so that the fine aggregate proportions change 44% to 38%, the compressive strength of concrete using the bottom ash could even be higher than BAO concrete. And the chloric content of concrete using the bottom ash increased as the replacement ratio of bottom ash increased, but it is satisfied with the chloric content of fresh concrete 0.30 kg/m2 below (concrete standard specification regulation value).

Research on the Feasibility of Concrete Incorporating Water Purification Sludge

2020 ◽  
Vol 1005 ◽  
pp. 47-56
Author(s):  
Chung Hao Wu ◽  
Hsien Sheng Peng ◽  
How Ji Chen
Keyword(s):  
Compressive Strength ◽  
Water Purification ◽  
Fine Aggregate ◽  
Test Results ◽  
Replacement Level ◽  
Replacement Ratio ◽  
Water Treatment Plants ◽  
Mix Proportion ◽  
Design Requirements ◽  
Compressive Strength Of Concrete

This study aims to develop the mix proportion of concrete incorporating water purification sludge (WPS), as parts of fine aggregate and consequently investigate its mechanical properties and durability. The experiments involve three sludges from Da-Nan, Lin-Nei and Nan-Hua water treatment plants in Taiwan. In addition to the control mixture without WPS, four replacement levels of 20%, 40%, 60% and 80% of fine aggregate were selected for preparing the concrete mixture. The concretes tested were designed to have three target compressive strengths of 14MPa, 18MPa and 21MPa. Test results show that the compressive strengths of the Da-Nan and Lin-Nei WPS concretes meet the design requirements, and the strength of the Nan-Hua WPS concrete is lower to be only suitable for application in low strength concretes. The shrinkage deformation of the Da-Nan and Lin-Nei WPS concretes increase with the increase of sludge replacement level, however, the shrinkage deformation decreases with the increase of the compressive strength of concrete. If the sludge replacement ratio is less than 40%, its effect on the compressive strength of the Da-Nan and Lin-Nei WPSs concrete is limited whether they are cured in water or in the air.

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