Early-age and long-term strength development of high-performance concrete with SAP

2021 ◽  
Vol 267 ◽  
pp. 121798
Author(s):  
Babatunde J. Olawuyi ◽  
Adewumi J. Babafemi ◽  
William P. Boshoff
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Strength Development ◽  
Early Age ◽  
Term Strength

scholarly journals Cost-Effective High-Performance Concrete: Experimental Analysis on Shrinkage

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2730
Author(s):  
Barbara Kucharczyková ◽  
Dalibor Kocáb ◽  
Petr Daněk ◽  
Ivailo Terzijski
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Setting Time ◽  
Mechanical Strain ◽  
Cost Effective ◽  
Strain Gauges ◽  
Early Age ◽  
Dry Air ◽  
First Case

This paper focuses on the experimental determination of the shrinkage process in Self-Compacting High-Performance Concrete (SCC HPC) exposed to dry air and autogenous conditions. Special molds with dimensions of 100 mm × 60 mm × 1000 mm and 50 mm × 50 mm × 300 mm equipped with one movable head are used for the measurement. The main aim of this study is to compare the shrinkage curves of SCC HPC, which were obtained by using different measurement devices and for specimens of different sizes. In addition, two different times t0 are considered for the data evaluation to investigate the influence of this factor on the absolute value of shrinkage. In the first case, t0 is the time of the start of measurement, in the second case, t0 is the setting time. The early-shrinkage (48 h) is continuously measured using inductive sensors leant against the movable head and with strain gauges embedded inside the test specimen. To monitor the long term shrinkage, the specimens are equipped with special markers, embedded into the specimens’ upper surface or ends. These markers serve as measurement bases for the measurement using mechanical strain gauges. The test specimens are demolded after 48 h and the long term shrinkage is monitored using the embedded strain gauges (inside the specimens) and mechanical strain gauges that are placed, in regular intervals, onto the markers embedded into the specimens’ surface or ends. The results show that both types of measurement equipment give a similar result in the case of early age measurement, especially for the specimens cured under autogenous conditions. However, the early age and especially long term measurement are influenced by the position of the measurement sensors, particularly in the case of specimens cured under dry air conditions. It was proven that the time t0 have a fundamental influence on the final values of the shrinkage of investigated SCC HPC and have a significant impact on the conclusions on the size effect.

scholarly journals Utilizing Iron Ore Tailing as Cementitious Material for Eco-Friendly Design of Ultra-High Performance Concrete (UHPC)

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1829
Author(s):  
Gang Ling ◽  
Zhonghe Shui ◽  
Xu Gao ◽  
Tao Sun ◽  
Rui Yu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Carbon Emission ◽  
Iron Ore ◽  
High Performance Concrete ◽  
Cementitious Material ◽  
Early Age ◽  
Ultra High Performance Concrete ◽  
Iron Ore Tailing

In this research, iron ore tailing (IOT) is utilized as the cementitious material to develop an eco-friendly ultra-high performance concrete (UHPC). The UHPC mix is obtained according to the modified Andreasen and Andersen (MAA) packing model, and the applied dosage of IOT is 10%, 20%, and 30% (by weight), respectively. The calculated packing density of different mixtures is consistent with each other. Afterwards, the fresh and hardened performance of UHPC mixtures with IOT are evaluated. The results demonstrate that the workability of designed UHPC mixtures is increased with the incorporation of IOT. The heat flow at an early age of designed UHPC with IOT is attenuated, the compressive strength and auto shrinkage at an early age are consequently reduced. The addition of IOT promotes the development of long-term compressive strength and optimization of the pore structure, thus the durability of designed UHPC is still guaranteed. In addition, the ecological estimate results show that the utilization of IOT for the UHPC design can reduce the carbon emission significantly.

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.

scholarly journals Shrinkage Mitigation of an Ultra-High Performance Concrete Submitted to Various Mixing and Curing Conditions

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3982
Author(s):  
Cédric Androuët ◽  
Jean-Philippe Charron
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Water Immersion ◽  
Autogenous Shrinkage ◽  
Early Age ◽  
Curing Conditions ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
The Impact

Ultra-High Performance Concretes (UHPC) are cement-based materials with a very low water-to-binder ratio that present a very-high compressive strength, high tensile strength and ductility as well as excellent durability, making them very interesting for various civil engineering applications. However, one drawback of UHPC is their pretty high autogenous shrinkage stemming from their very low water-to-binder ratio. There are several options to reduce UHPC shrinkage, such as the use of fibers (steel fibers, polypropylene fibers, wollastonite microfibers), shrinkage-reducing admixtures (SRA), expansive admixtures (EA), saturated lightweight aggregates (SLWA) and superabsorbent polymers (SAP). Other factors related to curing conditions, such as humidity and temperature, also affect the shrinkage of UHPC. The aim of this paper is to investigate the impact of various SRA, different mixing and curing conditions (low to moderate mixing temperatures, moderate to high relative humidity and water immersion) as well as different curing starting times and durations on the shrinkage of UHPC. The major importance of the initial mixing and curing conditions has been clearly demonstrated. It was shown that the shrinkage of the UHPC was reduced by more than 20% at early-age and long-term when the fresh UHPC temperature was closer to 20 °C. In addition, curing by water immersion led to drastic reductions in shrinkage of up to 65% and 30% at early-age and long-term, respectively, in comparison to a 20% reduction for fog curing at early-age. Finally, utilization of a liquid polyol-based SRA allowed for reductions of 69% and 63% of early-age and long-term shrinkages, respectively, while a powder polyol-based SRA provided a decrease of 47% and 35%, respectively.

Properties of High Performance Concrete Containing Waste Glass Micro-Filler

2014 ◽  
Vol 604 ◽  
pp. 161-164 ◽  
Author(s):  
Genadijs Sahmenko ◽  
Nikolajs Toropovs ◽  
Matiss Sutinis ◽  
Janis Justs
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Glass Powder ◽  
High Performance Concrete ◽  
Setting Time ◽  
Ground Glass ◽  
Early Age ◽  
Strength Gain ◽  
Fluorescent Lamp

The article discusses possibilities for use fine ground glass obtained from fluorescent lamp utilisation as micro filler in High Performance Concrete (HPC). Investigated mix compositions are based on silica fume (SF) and SF combination with glass powder. Testing results indicates that replacing silica fume by additionally ground fluorescent glass (up to 50%) slightly increasing consumption of water and delaying setting time of cement paste. All HPC mixes with glass powder showing decreased early-age strength and considerable strength gain after long-term hardening. It is concluded, that the best way of glass application in HPC is use fine ground glass powder together with silica fume as complex admixture.

Early-Age Autogenous Shrinkage of High-Performance Concrete Columns by Embedded Fiber Bragg-Grating Sensor

2009 ◽  
Vol 419-420 ◽  
pp. 1-4 ◽  
Author(s):  
Ying Wei Yun ◽  
Ii Young Jang ◽  
Seong Kyum Kim ◽  
Seung Min Park
Keyword(s):  
Fiber Bragg Grating ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Autogenous Shrinkage ◽  
Strain Sensor ◽  
Bragg Grating ◽  
Early Age ◽  
Long Time ◽  
Sensor Temperature

High-performance concrete (HPC) as a promising construction material has been widely used in infrastructures and high-rise buildings etc. However, its pretty high autogenous shrinkage (AS) especially in its early age becomes one of the key problems endangering long-time durability of HPC structures. This paper carried out the early age AS research of large scaled HPC column specimens by embedded Fiber Bragg-Grating (FBG) strain sensor. Temperature compensation for FBG strain sensor by thermocouple was also attempted in this paper, and the results were reasonable and acceptable comparing with the result compensated by FBG temperature sensor. Reinforcement influence, size effect and temperature effect on HPC AS were also analyzed respectively in this paper.

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