Effect of Nano Materials on Durability of High Performance Concrete

2013 ◽  
Vol 742 ◽  
pp. 220-223 ◽  
Author(s):  
Yu Xi An
Keyword(s):  
Water Permeability ◽  
High Performance ◽  
High Performance Concrete ◽  
Shrinkage Strain ◽  
Nano Materials ◽  
Carbonation Depth ◽  
Shrinkage Cracking ◽  
Carbonation Resistance ◽  
Dry Shrinkage

The aim of this study was to study the effect of nanoSiO2 on durability of high performance concrete. Four different nanoSiO2 contents (1%, 2%, 3% and 4%) were used. The results indicate that the content of nanoSiO2 has great effect on the durability of high performance concrete. With the increase of nanoSiO2 content, both of the length of water permeability and the carbonation depth of concrete are decreasing gradually, and the water impermeability and the carbonation resistance of concrete are increasing gradually. However, with the increase of nanoSiO2 content, there is a tendency of increase on the dry shrinkage strain of 90 days of high performance concrete, and the anti-dry-shrinkage cracking property of concrete is decreasing.

scholarly journals Effects of nano silica on carbonation resistance of concrete

2019 ◽  
Vol 275 ◽  
pp. 02001
Author(s):  
Xin Wan ◽  
Chun-fa Su ◽  
Leo Gu Li
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Material ◽  
Nano Materials ◽  
Nano Silica ◽  
Carbonation Depth ◽  
Supplementary Cementitious Material ◽  
Carbonation Resistance ◽  
Cost Of Production

In tandem with recent development of nanotechnology and reduction in cost of production, many nano-materials have been tried in concrete. In this study, the effect of nano silica (NS) on the carbonation resistance of concrete was investigated by producing a number of trial concrete mixes with varying water and NS contents for carbonation depth test. The results demonstrated that the addition of NS could significantly reduce the 28-day and 56-day carbonation depths of concrete, indicating that NS may be a promising supplementary cementitious material for producing high-performance concrete.

Effect of silica fume on durability of concrete composites containing fly ash

2013 ◽  
Vol 20 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Peng Zhang ◽  
Qing-fu Li
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Shrinkage Strain ◽  
Carbonation Depth ◽  
Freeze Thaw ◽  
Slump Flow ◽  
Carbonation Resistance ◽  
Dry Shrinkage ◽  
Shrinkage Property ◽  
Durability Of Concrete

AbstractIn this paper, the effect of silica fume on the workability and durability of concrete composites containing fly ash, including water impermeability, dry shrinkage property, carbonation resistance and freeze-thaw resistance, are presented. Four different silica fume contents (3%, 6%, 9% and 12%) were used. The results indicate that the addition of silica fume has greatly improved the durability of water impermeability, the carbonation resistance and the freeze-thaw resistance of the concrete composites containing fly ash. With the increase in silica fume content, the length of water permeability and the carbonation depth of the specimens decrease gradually, and the relative dynamic elastic modulus of the specimens has a tendency to increase. However, the addition of silica fume has a little adverse effect on the workability and dry shrinkage property of concrete composites containing fly ash. With the increase in silica fume content, both the slump and the slump flow decrease gradually, and the dry shrinkage strain increases gradually.

Study on Carbonization Test of Manufactured Sand Concrete

2013 ◽  
Vol 423-426 ◽  
pp. 1036-1040
Author(s):  
Da Zhen Xu ◽  
Gu Hua Li ◽  
Zhuang Zhi Liao ◽  
Hai Wei Yan
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Mineral Admixtures ◽  
Test Results ◽  
Carbonation Depth ◽  
Manufactured Sand ◽  
Carbonation Resistance ◽  
Binder Ratio ◽  
The Impact ◽  
Water Binder Ratio

To study the impact of mineral admixtures and water-binder ratio on carbonization resistance of high performance manufactured sand concrete, high performance concrete of single mixed flyash, admixing silica fume and no admixture were compounded, carbonation depth of 3d, 7d, 14d and 28d was recorded by the way of indoor test. The test results show that with the decrease of water-binder ratio, carbonation resistance of high performance manufactured sand concrete increase, and when the concrete compressive strength is over 55Mpa, carbonation resistance is good, and when water-binder ratio is lower than 0.38, the impact of mineral admixtures on the carbonation resistance can be neglected.

Study on Carbonation Resistance of High-Performance Concrete with Large Amount of Fly Ash

2012 ◽  
Vol 476-478 ◽  
pp. 1688-1691 ◽  
Author(s):  
Xue Song Zhang
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Strength Development ◽  
Carbonation Depth ◽  
Concrete Carbonation ◽  
Carbonation Resistance ◽  
Development Characteristic ◽  
Compressive Strength Development

Based on the mechanism of concrete carbonation, the effects of content of fly ash in the binder, the water to binder ratios, compound activator, and long-term curing on the carbonation depth of fly ash high-performance concrete are investigated. Experiment results are analyzed and compared with compressive strength development characteristic of fly ash high-performance concrete, and some valuable conclusions are gained.

Cracking Risk Appraisal of High Performance Recycled Pavement Concrete and its Application

2011 ◽  
Vol 382 ◽  
pp. 256-259
Author(s):  
Li Juan Zhang ◽  
Yi Dong Xu ◽  
Lei Pan ◽  
Bing Bing Wang ◽  
Chi Lou
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Shrinkage Cracking ◽  
Risk Appraisal ◽  
Plastic Shrinkage ◽  
Evaluation Test ◽  
Dry Shrinkage ◽  
Cracking Risk ◽  
Pavement Concrete

Based on the technology of high performance concrete, high performance recycled pavement concrete (HPRPC) were developed by double -mixture of fly ash and superplasticizer. The dry shrinkage and plastic shrinkage cracking evaluation test were conducted. As is shown by the results, the compressive strength of HPRPC at 28d are exceed in 60MPa and dry shrinkage at 120d are less than 500με. By contrast, the cracking -resistant performance of HPRPC-7 is superior to that of HPRPC-2.

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

Strengthening of a Bridge Pier with HPC: Modeling of Restrained Shrinkage Cracking

2016 ◽  
Vol 711 ◽  
pp. 1027-1034 ◽  
Author(s):  
Adriano Reggia ◽  
Sara Sgobba ◽  
Fabio Macobatti ◽  
Cristina Zanotti ◽  
Fausto Minelli ◽  
...  
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Numerical Models ◽  
Experimental Tests ◽  
Concrete Bridges ◽  
Restrained Shrinkage ◽  
Shrinkage Cracking ◽  
Rc Structures ◽  
Restrained Shrinkage Cracking

After more than fifty years from the opening of the largely discussed “Autostrada del Sole” Highway in 1964, the infrastructure system in Italy appears marked by the passing of time, similarly to what observed in several other countries worldwide. The great heterogeneity of the Italian landscape has determined a great variety of construction types, such as large span concrete bridges over the northern rivers and large arch concrete bridges over the valleys of the central region. Increment of vehicle traffic and new seismic regulations are setting new requirements to adapt the existing infrastructure, which should be otherwise replaced. Moreover, reinforced concrete (RC) aging and deterioration have led to structural and material degradation, including severe cracking and corrosion. Specialized materials such as High Performance Concrete (HPC) could represent a viable convenient solution for repairing, strengthening and retrofitting of RC structures as both structural capacity and durability can be refurbished. However, alongside high mechanical performance, HPC is characterized by a high cracking sensitivity at very early age, due to its high stiffness and shrinkage. Restrained shrinkage cracking, particularly significant in repaired structures where the existing concrete generates a considerable restraint against the free movement of the repair material, may represent a limit to the effective application of these materials. For this reason, shrinkage compatibility of HPC with the existing concrete substrate needs to be experimentally and numerically assessed. A study is herein presented where, based on experimental tests, different numerical models are developed and compared to assess and eventually minimize the risk of shrinkage cracking in bridge piers strengthened with HPC.

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