scholarly journals Influencia del uso de metacaolín y el humo de sílice en el desarrollo de la resistencia a compresión del hormigón de altas prestaciones y su relación con la microestructura = Influence of metakaolin and silica fume in the development of compressive strength of high performance concrete and its relationship with the microstructure

2020 ◽  
Vol 6 (1) ◽  
pp. 70
Author(s):  
Julio A. Paredes ◽  
Jaime C. Gálvez ◽  
Marcos G. Alberti ◽  
Alejandro Enfedaque
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
E. H. Kadri ◽  
S. Aggoun ◽  
S. Kenai ◽  
A. Kaci

The compressive strength of silica fume concretes was investigated at low water-cementitious materials ratios with a naphthalene sulphonate superplasticizer. The results show that partial cement replacement up to 20% produce, higher compressive strengths than control concretes, nevertheless the strength gain is less than 15%. In this paper we propose a model to evaluate the compressive strength of silica fume concrete at any time. The model is related to the water-cementitious materials and silica-cement ratios. Taking into account the author's and other researchers’ experimental data, the accuracy of the proposed model is better than 5%.


2014 ◽  
Vol 627 ◽  
pp. 445-448 ◽  
Author(s):  
Young Il Jang ◽  
Wan Shin Park ◽  
Sun Woong Kim ◽  
Song Hui Yun ◽  
Hyun Do Yun ◽  
...  

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.


2021 ◽  
Vol 72 (1) ◽  
pp. 76-83
Author(s):  
Lam Le Hong ◽  
Lam Dao Duy ◽  
Huu Pham Duy

The demand for High Performance Concrete (HPC) is steadily increasing with massive developments. Conventionally, it is possible to use industrial products such as silica fume (SF), fly ash, as supplementary cementitious materials (SCM), to enhance the attributes of HPC. In recent years, nano-silica (NS) is used as an additive in added mainly to fill up the deviation arises with the addition of SF for HPC. This study aims to optimize the proportion of NS (produced in Vietnam) in the mixture used for fabricating 70 MPa high-performance concrete. SiO2 powder with particle size from 10 to 15 nm were used for mixing. A series of compressive strength test of HPC with nano-SiO2 varied from 0 to 2.8 percent of total of all binders (0%, 1.2%, 2%, 2.8%), and the fixed percentage of silica fume at 8% were proposed. Results show compressive strength increases with the increase of nano-SiO2, but this increase stops after reaching 2%. And at day 28 of the curing period, only concrete mixture containing of 8% silica fume and 2% nano-SiO2, had the highest compressive strength.


2016 ◽  
Vol 677 ◽  
pp. 98-102 ◽  
Author(s):  
Michal Ženíšek ◽  
Tomáš Vlach ◽  
Lenka Laiblová

Durability and high strength of concrete are closely associated with low porosity and generally denser material structure. This is achieved using the addition, which include also silica fume. This article deal with an effective dosage of silica fume in high performance concrete, in a proportion of 0-25 % by the weight of cement. Compressive strength, rheological behaviour and economic benefits were the main questions in this work. The expected increase in compressive strength showed itself in lower doses of silica fume, while higher doses did not produce a further increase in strength. In the case of rheological behaviour, we can confirm lower bleeding and segregation, but also faster drying of the surface layer. From the economic point of view, a small doses of silica fume are better, because then we have observed the highest increase in strength.


2013 ◽  
Vol 372 ◽  
pp. 231-234
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Nam Yong Eom ◽  
Sun Woong Kim ◽  
Do Gyeum Kim ◽  
...  

In this study, some experimental investigations on the development of mechanical properties with age of high performance concrete (HPC) incorporated with blast furnace slag with fly ash or silica fume have been reported. Four different blended HPC were prepared in 0.40 water-binder ratio. At every four mixtures, the compressive strength, splitting tensile strength and modulus of elasticity at 7 and 28 days have been observed for HPC developments. Consequently, only replacement of silica fume significantly increases the mechanical properties in terms of compressive strength, splitting tensile strength and modulus of elasticity.


2021 ◽  
Vol 895 ◽  
pp. 59-67
Author(s):  
Mayadah W. Falah ◽  
Alaa Adnan Hafedh ◽  
Safa A. Hussein ◽  
Zainab S. Al-Khafaji ◽  
Ali A. Shubbar ◽  
...  

To manufacture high-strength and high-performance concrete, the incorporation of silica fume with concrete was becoming popular nowadays. When utilizing various amounts of cement substitute products, the design becomes even more complicated. The latest research has been dedicated to researching the applicability of cement substitute products for cement kiln dust (CKD) and silica fume (SF). In permeability and compressive strength terms, the effect of these components on the efficacy of the concrete would be studied. Also, the materials proposed might limit greenhouse gas emissions, which will mitigate climate change on other causes of global pollution. Casting a standard concrete cube (100 percent OPC) equivalent to (150 gm) would initiate the experiment, which was utilized later for comparative purposes. The industrial waste materials (SF and CKD) was be applied as cement substitution proportions (10 percent, 20 percent, and 30 percent) of the dry cement weight at varying percentages of each component (5 percent, 10 percent, and 15 percent). Eventually, after 7, 14, 28 days, the compressive strength shift would be calculated. The permeability of the latest concrete will be checked after (7, 14, and 28) days of healing utilizing ultrasonic pulse velocity (UPV) technology. The experimental findings indicate that with a specimen comprising 20 percent of (SF and CKD) relative to (100 percent OPC) specimen, there is an improvement in compressive intensity and pulse velocity values in various curing times and specimens of various (SF and CKD) specimen M3 have a decrease in pulse velocity value after 7 curing days.


2008 ◽  
Vol 385-387 ◽  
pp. 701-704 ◽  
Author(s):  
Jung Jun Park ◽  
Gum Sung Ryu ◽  
Su Tae Kang ◽  
Sung Wook Kim

Silica fume constitutes an element of extreme importance in improving the strength and fluidity of UHPC. The adopted amount of silica fume generally is generally exceeding 25% of cement in weight but the influence of this amount on the properties of UHPC is still remaining as a domain to be investigated. Accordingly, this paper investigates the effects of the amount of silica fume on the mechanical characteristics of the fluidity, compressive strength, elastic modulus and flexural strength and on the micro structure of UHPC by means of SEM and MIP. Results revealed that adequate amount of silica fume is improving the fluidity and strength. MIP tests demonstrated that such improvement is brought by the increase of hydrates due to the pozzolan reaction and the effective densification inside concrete due to the filler. It seemed also that similar mechanical characteristics can be obtained for a volumetric ratio to cement ranging between 10 and 25%.


2016 ◽  
Vol 249 ◽  
pp. 119-124 ◽  
Author(s):  
Mohammad Ali Mosaberpanah ◽  
Ozgur Eren

This paper aims to model the effect of density in 7, 14, 28 days on compressive strength of Ultra High Performance Concrete (UHPC) in same compaction and curing conditions by Design of Experiments (DOE) methodology using vary range of 5 variables: Silica fume (SF), Steel Fiber, Cement 42.5, Superplasticizer (SP), and water cemetiotious ratio (w/c).The results shows the significance effect of density on compressive strength of UHPC in different days, The models are valid for the mixes made with 1.0 sand, 0.15-0.30 silica fume amount, 0.70-1.30 cement amount, 0.10- 0.20 steel fiber, 0.04- 0.08 superplasticizer (all values are by sand by weight mass) and 0.18- 0.32 water cementitious ratio.


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