scholarly journals Experimental Study on Special Testing Strength Curve for Compressive Strength Evaluation by Rebound Method

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wei Yuan ◽  
Renfeng Yang ◽  
Jianyou Yu ◽  
Xiujie Han
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mineral Admixtures ◽  
Strength Evaluation ◽  
Winter Olympics ◽  
Mixing Ratios ◽  
Concrete Members ◽  
Rebound Number ◽  
Strength Curve ◽  
Curing Age

This article aims to improve the accuracy and predictability of rebound method in compressive strength evaluation of concrete members of the Yanchong Expressway, which is an important traffic guarantee project for the 2022 Winter Olympics Games in Zhangjiakou city, Hebei Province, China. For this purpose, concrete specimens were prepared by the mixing ratios of C35, C40, and C50. First of all, the paper investigated the effects of curing age, types, and dosage of mineral admixtures (fly ash and slag) on concrete rebound number and compressive strength. Then, the special testing strength curves of 7 d and 90 d curing age were proposed. The results showed that the average relative errors of the special testing strength curves were reduced by 35.99% and 20.26% respectively, compared with the national testing strength curve. Fly ash and slag were beneficial to the growth of concrete rebound numbers but cannot contribute to the growth of concrete compressive strength (except for fly ash single-mixed with 15% dosage). The present results can provide a significant reference for the compressive strength evaluation and later maintenance of concrete members of the Yanchong Expressway or other projects with tight construction period in this area.

scholarly journals Influence of boulder machine-made sand powder on compressive strength of concrete

2021 ◽  
Vol 293 ◽  
pp. 02023
Author(s):  
Pengtao Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Early Stage ◽  
Cementitious Materials ◽  
Mineral Admixtures ◽  
Rock Powder ◽  
Manufactured Sand ◽  
Slag Powder ◽  
Compressive Strength Of Concrete ◽  
Curing Age

In order to recycle the boulder powder produced in the process of manufactured sand production and reduce the cost of engineering concrete, this article studied the influence of boulders powder on the compressive strength of concrete. The results show that in the early stage of concrete test, the compressive strength of rock powder concrete is slightly lower than of fly ash and mineral powder concrete. With the development of curing age, the strength of boulders powder concrete developed slower. As the increase of boulders powder content, the compressive strength of different curing age gradually decreased, and it was suggested that the content of boulders powder should be controlled within 20% of cementitious materials mass. The positive effect of boulders powder fineness on the strength of concrete is limited, so it is suggested to use unprocessed collected boulders powder in the project, which is economical and environmentally friendly. With the adjustment of water-to-binder ratio, boulders powder can be prepared with different strength grades of concrete to meet the needs of engineering; the composite of boulders powder with traditional mineral admixtures, such as fly ash, and especially granulated blast furnace slag powder, can significantly improve the strength of concrete.

scholarly journals Biofuel Combustion Fly Ash Influence on the Properties of Concrete

2016 ◽  
Vol 7 (5) ◽  
pp. 546-550
Author(s):  
Aurelijus Daugėla ◽  
Džigita Nagrockienė ◽  
Laurynas Zarauskas
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Water Absorption ◽  
Frost Resistance ◽  
Ash Content ◽  
Mineral Admixtures ◽  
Binding Agent ◽  
Materials Used ◽  
Plasticizing Admixture

Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.

Study on the Durability of Concrete with Mineral Admixtures to Sulfate Attack by Wet-Dry Cycle Method

2011 ◽  
Vol 295-297 ◽  
pp. 165-169
Author(s):  
Guan Guo Liu ◽  
Jing Ming ◽  
Xiong Wen Zhang ◽  
Ai Bin Ma
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sulfate Attack ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Change Environment ◽  
Physical Mechanisms ◽  
Chemical Attack ◽  
Tidal Area

Sulfate attack is one of several chemical and physical mechanisms of concrete deterioration. In actual situation, concrete structures always suffer from the coupled effects of multifactor such as wet-dry cycle and sulfate attack when exposed to tidal area or groundwater level change environment. Partial replacement of cement with mineral admixture is one of the efficient methods for improving concrete resistance against sulfate attack. In this regard, the resistance of concrete with fly ash and slag to sulfate attack was investigated by wet-dry cycle method. The degree of sulfate attack on specimens after different cycles was observed using scanning electron microscopy. The results of compressive strength and percentage of compressive strength evolution factor at various cycling times show an increase in the sulfate resistance of concrete with 60% of fly ash and slag than that only with 40% fly ash. The microstructural study indicates that the primary cause of deterioration of concrete under wet-dry cycle condition is swelling of the sulfate crystal rather chemical attack.

Effect of steel slag powder, fly ash, and silica fume on the mechanical properties and durability of cement mortar

2019 ◽  
Vol 9 (9) ◽  
pp. 1049-1054
Author(s):  
Yunxia Lun ◽  
Fangfang Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Slag Powder ◽  
Steel Slag Powder

This study is aimed at exploring the effect of steel slag powder (SSP), fly ash (FA), and silica fume (SF) on the mechanical properties and durability of cement mortar. SSP, SF, and FA were used as partial replacement of the Ordinary Portland cement (OPC). It was showed that the compressive and bending strength of steel slag powder were slightly lower than that of OPC. An increase in the SSP content caused a decrease in strength. However, the growth rate of compressive strength of SSP2 (20% replacement by the weight of OPC) at the curing ages of 90 days was about 8% higher than that of OPC, and the durability of SSP2 was better than that of OPC. The combination of mineral admixtures improved the later strength, water impermeability, and sulfate resistance compared with OPC and SSP2. The compressive strength of SSPFA (SSP and SF) at 90 days reached 70.3 MPa. The results of X-ray diffraction patterns and scanning electron microscopy indicated that SSP played a synergistic role with FA or SF to improve the performance of cement mortar.

The Influence of Combined Admixture of Super-Fine Limestone Powder and Low-Quality Fly Ash on the Performance of Cement Mortar

2013 ◽  
Vol 652-654 ◽  
pp. 1181-1184
Author(s):  
Guo Qiang Xu ◽  
Zhi Guo You ◽  
Lin Gao ◽  
Dian Li Han
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Test Results ◽  
Maximum Compressive Strength

The influence of admixture of super-fine limestone powder and low-quality fly ash in different proportions on the fluidity and strength of cement mortar is studied. The test results show that the mortar fluidity increases with the increase of the super-fine limestone powder (the mixing amount of fly ash reduces), and the strength of cement mortar can improve when limestone powder and low-quality fly ash are combined admixed to a certain ratio. The maximum flexural strength of the 28d mortar is 9.8MPa and its maximum compressive strength is 42.2MPa, and at this time, the limestone powder accounts for 33.3% of the mineral admixtures. However, when the mixing amount of super-fine limestone powder is over a certain range, the strength of 28d cement mortar will reduce.

Size Effect on Compressive Strength and Modulus of Elasticity in High Performance Concrete

2013 ◽  
Vol 634-638 ◽  
pp. 2742-2745 ◽  
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Nam Yong Eom ◽  
Do Gyeum Kim ◽  
Jea Myoung Noh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Size Effect ◽  
Modulus Of Elasticity ◽  
High Performance ◽  
High Performance Concrete ◽  
Type A ◽  
Type B ◽  
Replacement Ratio ◽  
Curing Age

This study undertook the research of size effect on compressive strength and modulus of elasticity, respectively. The parameters of this study are curing age and fly ash replacement ratio to investigate size effect of Type A (100mm x 200mm) and Type B (150mm x 300mm) specimens in high performance concrete. On this study, high performance concrete was fabricated with different FA contents of 10%, 20% and 30%. The measurements were performed on days 28 and 91.

scholarly journals Properties and Environmental Features of Bricks Made From Textile Waste Sludge

2021 ◽  
Vol 2070 (1) ◽  
pp. 012185
Author(s):  
R Premkumar ◽  
J Khaja mohideen ◽  
M Mathan kumar ◽  
T Sundara moorthi ◽  
X. Celestin
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Construction Materials ◽  
Project Work ◽  
Weight Density ◽  
Sludge Waste ◽  
Textile Sludge ◽  
Quarry Dust ◽  
Curing Age

Abstract In recent years, there has been a lot of attention paid to the use of textile sludge waste-based products in the building industry to develop ecologically friendly construction materials. An experimental examination of the characteristics of bricks incorporating textile sludge waste and fly ash is presented in this work. In fly ash bricks, fly ash is used to replace textile sludge waste in the following proportions: For the blend percentage of cement, fly ash, and quarry dust, a 230mm × 100mm × 75mm sample size was used. For varying amounts of the components indicated previously, the findings indicate how compressive strength and water absorption fluctuate with curing age. Then we can cast bricks with various mixed proportions of cement, sludge waste, fly ash, and quarry dust using the 230mm × 100mm × 75mm specimen size. After that, the weight, compressive strength, and water absorption of textile sludge with different concentrations of fly ash bricks were compared. This inquiry is primarily concentrated on maximizing the compressive strength of newly produced bricks while limiting weight density and water absorption through extensive laboratory work. The recognition of elements influencing the diverse qualities of bricks is a clear purpose of pursuing this issue as project work.

scholarly journals Influence of curing age on high-temperature properties of additive manufactured geopolymer mortar

2020 ◽  
Vol 218 ◽  
pp. 03019
Author(s):  
Xiaohong Yin ◽  
Xiaodong Wang ◽  
Yuan Fang ◽  
Zhu Ding
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Flexural Strength ◽  
High Temperature Properties ◽  
Before And After ◽  
3D Printed ◽  
Curing Age

Some researches have been conducted on the application of geopolymer in 3D printing. However, there is no publication about the high-temperature properties of 3D printed geopolymer made from fly ash, slag, and metakaolin. This paper presents the experimental research on the mechanical properties of 3D printed geopolymer after being exposed to elevated empratures. The effects of curing age on high-temperature properties are analyzed. The heating temperasures were 300 °C, 600 °C, and 900 °C, and the holding time was one hour. After exposure to temperatures, the flexural strength of 3D printed geopolymer exhibited different change trends with increasing curing age for different exposure temperatures. Before and after exposure to elevated temperature, the 3D printed geopolymer experienced significant anisotropic compressive strengths. The change trends of compressive strength at different exposure temperatures wit hincreasing curing ages were different from each other on different loading directions.

Influence of Mineral Admixtures on Mortar Brittleness

2010 ◽  
Vol 168-170 ◽  
pp. 281-285
Author(s):  
Ben Lin Xiao ◽  
Li Hua Li ◽  
Hui Ming Tang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mineral Admixtures ◽  
Test Results ◽  
Paper Test

The influence of mineral admixtures on mortar brittleness is analysed in this paper. Test results show that the mortar brittleness increases with the increasing of compressive strength and the passage of age. When the content of binding materials rises, the compressive strength also increases, but the brittleness decreases at the same time. The more the content of fly ash is, the more the brittleness falls. Silica fume added can not only enhance compressive strength but also reduce brittleness of the mortar. MgO added can cut down the brittleness, but can reduce the compressive strength a little at the same time, especially for early compressive strength.

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