Study on early Mechanical Performance of High Performance Concrete with Low Clinker Influenced by Rubber Powder

2014 ◽  
Vol 584-586 ◽  
pp. 1738-1741
Author(s):  
Qing Hai Meng ◽  
Li Hua Lv ◽  
Xu Yan
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
High Performance ◽  
Bending Strength ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Fine Aggregate ◽  
Rubber Powder ◽  
Concrete Mechanical Properties ◽  
Strength And Ductility

Selecting rubber powders, which is divided into 80 mesh and 150 mesh, as the research object, to understand the influence of high performance of lower clinker concrete mechanical properties of rubber powder with different varieties and volume. Taking the compressive strength, flexural strength and ratio of flexural strength to compressive strength as an indicator, the thesis explores the influence of the high performance concrete with low clinker, which rubber powder are mixed into as fine aggregate, on the compressive strength bending strength and ductility.

Influence of Silica Fume on High-Performance Concrete

2014 ◽  
Vol 670-671 ◽  
pp. 437-440 ◽  
Author(s):  
Fan Wang ◽  
Shan Suo Zheng ◽  
Xiao Fei Wang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Split Tensile Strength ◽  
Binder Ratio ◽  
Water Binder Ratio

With the improvement of concrete materials and the emergence of new materials, adding silica fume to high-performance concrete (HPC) has been one of the important ways in concrete technology. In this paper, through experimental study on the mechanical performance of HPC with 5%, 10%, 15% and 20% silica fume replacing cement for different water-binder ratio, along with polycarboxylates high performance water-reducing admixture, silica fume has large effects on 28d compressive strength, split tensile strength and flexural strength of the HPC. Meanwhile, due to the different level of water-binder ratio, the relationship between split tensile strength, flexural strength and compressive strength is also obvious linear.

EXPERIMENTAL STUDY ON DURABILITY OF ROOM TEMPERATURE CURING UFC MORTAR

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Haruka Murakami ◽  
Hiromi Fujiwara ◽  
Masanori Maruoka ◽  
Takahumi Watanabe ◽  
Koji Satori
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
High Performance ◽  
Room Temperature ◽  
Bending Strength ◽  
High Performance Concrete ◽  
Drying Shrinkage ◽  
Concrete Repair ◽  
Repair Materials ◽  
Low Salt

In recent years, as structures become higher, larger, and more durable concrete whose compressive strength of the concrete is 150 N/mm 2 or more have been put to practical use. It is for this reason that it is necessary to develop strengthening materials with equal or better performance. Furthermore, the development of high-performance concrete repair materials is carried out because demand to seismic strengthening and repair increases. In this study, considering these circumstances, it was conducted an experimental study with the aim of developing a repair material using room temperature curing UFC (R-UFC). A binder composition preparation of the R-UFC has excellent fluidity under pressure. It was achieved that high-grade thixotropy, high compressive strength, and high bending strength. It can also be sprayed continuously because of its high thixtoropy. It was confirmed that the sprayed thickness was reached to 20mm by one work. Durability of this R-UFC was investigated and it was confirmed the high sulfate resistance, small drying shrinkage and low salt permeability.

scholarly journals Effect of Mineral Aggregates and Chemical Admixtures as Internal Curing Agents on the Mechanical Properties and Durability of High-Performance Concrete

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2090 ◽  
Author(s):  
Francisco Javier Vázquez-Rodríguez ◽  
Nora Elizondo-Villareal ◽  
Luz Hypatia Verástegui ◽  
Ana Maria Arato Tovar ◽  
Jesus Fernando López-Perales ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Ions ◽  
Internal Curing ◽  
Fine Aggregate ◽  
Pumice Stone ◽  
Chemical Admixtures ◽  
Mineral Aggregates

In the present work, the effect of mineral aggregates (pumice stone and expanded clay aggregates) and chemical admixtures (superplasticizers and shrinkage reducing additives) as an alternative internal curing technique was investigated, to improve the properties of high-performance concrete. In the fresh and hardened state, concretes with partial replacements of Portland cement (CPC30R and OPC40C) by pulverized fly ash in combination with the addition of mineral aggregates and chemical admixtures were studied. The physical, mechanical, and durability properties in terms of slump, density, porosity, compressive strength, and permeability to chloride ions were respectively determined. The microstructural analysis was carried out by scanning electronic microscopy. The results highlight the effect of the addition of expanded clay aggregate on the internal curing of the concrete, which allowed developing the maximum compressive strength at 28 days (61 MPa). Meanwhile, the replacement of fine aggregate by 20% of pumice stone allowed developing the maximum compressive strength (52 MPa) in an OPC-based concrete at 180 days. The effectiveness of internal curing to develop higher strength is attributed to control in the porosity and a high water release at a later age. Finally, the lowest permeability value at 90 days (945 C) was found by the substitutions of fine aggregate by 20% of pumice stone saturated with shrinkage reducing admixture into pores and OPC40C by 15% of pulverized fly ash. It might be due to impeded diffusion of chloride ions into cement paste in the vicinity of pulverized fly ash, where the pozzolanic reaction has occurred. The proposed internal curing technology can be considered a real alternative to achieve the expected performance of a high-performance concrete since a concrete with a compressive strength range from 45 to 67 MPa, density range from 2130 to 2310 kg/m3, and exceptional durability (< 2000 C) was effectively developed.

The ability of high performance concrete to resist high temperature

2017 ◽  
Vol 8 (4) ◽  
pp. 392-401 ◽  
Author(s):  
Hassan A.M. Mhamoud ◽  
Jia Yanmin
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Mass Loss ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Sharp Decrease ◽  
Test Results ◽  
Content Type ◽  
Chinese Standard

Purpose This study aims to focus on the resistance to elevated temperatures of up to 700ºC of high-performance concrete (HPC) compared to ordinary Portland concrete (OPC) with regards to mass loss and residual compressive and flexural strength. Design/methodology/approach Two mixtures were developed to test. The first mixture, OPC, was used as the control, and the second mixture was HPC. After 28 days under water (per Chinese standard), the samples were tested for compressive strength and residual strength. Findings The test results showed that at elevated temperatures of up to 500ºC, each mixture experienced mass loss. Below this temperature, the strength and the mass loss did not differ greatly. Originality/value When adding a 10 per cent silica fume, 25 per cent fly, 25 per cent slag to HPC, the compressive strength increased by 17 per cent and enhanced the residual compressive strength. A sharp decrease was observed in the residual flexural strength of HPC when compared to OPC after exposure to temperatures of 700ºC.

Influence of Cold Weather on Compressive Strength in High Performance with Silica Fume

2014 ◽  
Vol 627 ◽  
pp. 445-448 ◽  
Author(s):  
Young Il Jang ◽  
Wan Shin Park ◽  
Sun Woong Kim ◽  
Song Hui Yun ◽  
Hyun Do Yun ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Weather Condition ◽  
Weather Conditions ◽  
Cold Weather ◽  
Binder Ratio ◽  
Hot Weather

This paper addresses the influence of cold weather on the compressive strength of high performance concrete with silica fume under different curing days. Test variables of this study are weather condition (5°C, -5°C and-15°C) and different curing days (7days and 28 days). In this work, the specimen was designed a water-binder ratio of 0.34. One batches of concrete were prepared for each mixing hour, and the compressive strength of cylindrical concrete specimens was measured after 7 and 28 days. Test results for concrete compressive strength show that the concrete’s best mechanical performance occurred when there was the least difference between ambient temperature and concrete temperature, that is, during the later hours of the day in hot weather conditions.

scholarly journals The Statistical Analysis of Relation between Compressive and Tensile/Flexural Strength of High Performance Concrete

2016 ◽  
Vol 62 (4) ◽  
pp. 95-108 ◽  
Author(s):  
M. Kępniak ◽  
P. Woyciechowski
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Influential Factors ◽  
Experimental Results ◽  
Model Code ◽  
Splitting Test ◽  
Model Code 2010

AbstractThis paper addresses the tensile and flexural strength of HPC (high performance concrete). The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.

scholarly journals Mechanical Performance and Microstructure of Ultra-High-Performance Concrete Modified by Calcium Sulfoaluminate Cement

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Meimei Song ◽  
Chuanlin Wang ◽  
Ying Cui ◽  
Qiu Li ◽  
Zhiyang Gao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Ultra High Performance Concrete ◽  
Maximum Heat ◽  
Degree Of Hydration ◽  
Calcium Sulfoaluminate ◽  
Shrinkage Property

High autogenous shrinkage property is one of the disadvantages of ultra-high-performance concrete (UHPC), which may induce early age cracking and threaten the safety of concrete structure. In the present study, different dosages of calcium sulfoaluminate (CSA) cement were added in UHPC as an effective expansive binder. Hydration mechanism, autogenous shrinkage property, and compressive strength of UHPC were carried out to investigate the effect of CSA addition on the mechanical properties of UHPC. Scanning electron microscopy was also employed to characterize the intrinsic microstructural reasons relating to the changes in macroproperties. Based on the XRD diagram, increasing formation of ettringite and Ca(OH)2 can be found with increasing CSA content up to 15%. In the heat flow results of UHPC with 10% CSA addition, the maximum heat release increases to 2.6 mW/g, which is 8.3% higher than the reference UHPC, suggesting a higher degree of hydration with CSA addition. The results in autogenous shrinkage show that CSA expansion agent plays a significantly beneficial role in improving the autogenous shrinkage of UHPC. The corresponding autogenous shrinkage of UHPC is −59.66 μ ε , −131.11 μ ε , and −182.31 μ ε , respectively, at 7 d with 5%, 10%, and 15% addition, which is 108%, 117%, and 123% reduction compared to the reference specimen without CSA. In terms of compressive strength, UHPC with 5%, 10%, 15%, and 20% CSA addition has 10.5%, 17.4%, 30.2%, and 22.1% higher compressive strength than that for the reference UHPC at 28 d. Microstructural study shows that there is an extremely dense microstructure in both the bulk matrix and interfacial transition zone of UHPC with 10% CSA addition, which can be attributed to the higher autogenous shrinkage property and can therefore result in higher mechanical performance.

scholarly journals Behavior of HPC with Fly Ash after Elevated Temperature

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Huai-Shuai Shang ◽  
Ting-Hua Yi
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Ultrasonic Velocity ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Surface Characteristics ◽  
Effect Of Temperature ◽  
Cleavage Strength

For use in fire resistance calculations, the relevant thermal properties of high-performance concrete (HPC) with fly ash were determined through an experimental study. These properties included compressive strength, cubic compressive strength, cleavage strength, flexural strength, and the ultrasonic velocity at various temperatures (20, 100, 200, 300, 400 and 500∘C) for high-performance concrete. The effect of temperature on compressive strength, cubic compressive strength, cleavage strength, flexural strength, and the ultrasonic velocity of the high-performance concrete with fly ash was discussed according to the experimental results. The change of surface characteristics with the temperature was observed. It can serve as a reference for the maintenance, design, and the life prediction of high-performance concrete engineering, such as high-rise building, subjected to elevated temperatures.

scholarly journals The use of ceramics as an internal curing agent in high performance concrete with variable temperature curing to improve mechanical characteristics

2022 ◽  
Vol 961 (1) ◽  
pp. 012024
Author(s):  
Abdulrasool Thamer Abdulrasool ◽  
Noor R. Kadhim ◽  
Safaa S. Mohammed ◽  
Ahmed Abdulmueen Alher
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Mechanical Characteristics ◽  
High Performance Concrete ◽  
Variable Temperature ◽  
Porous Ceramic ◽  
Autogenous Shrinkage ◽  
Internal Curing ◽  
Fine Aggregate ◽  
Fine Aggregates

Abstract Concrete curing is one of the most significant factors in the development of compressive strength, and a high temperature difference during curing may reduce strength. The microcracks created in the concrete as a result of the constant temperature change cause this exudation. Internal curing has become popular for decreasing the risk of early-age cracking in high-performance concrete by limiting autogenous shrinkage (HPC). This study looks at the effectiveness of internal wet curing offered by a new kind of aggregate called “recycled waste porous ceramic fine aggregates”. The evolution of measured mechanical characteristics is examined on three distinct HPCs, both with and without internal curing materials. Ceramic fine aggregates were used to replace two different quantities of regular weight fine aggregate. Ceramic fine aggregates were shown to be quite beneficial for internal cure. It has been discovered that incorporating 20% ceramic fine aggregates into HPC improves the properties of the material, resulting in low internal stress and a large improvement in compressive strength. It should be emphasized that, unlike some traditional lightweight aggregates, no loss in compressive strength has been seen for the various quantities of ceramic fine aggregates introduced at either early or later ages.

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