Development of an eco-friendly Ultra-High Performance Concrete (UHPC) with efficient cement and mineral admixtures uses

2015 ◽  
Vol 55 ◽  
pp. 383-394 ◽  
Author(s):  
R. Yu ◽  
P. Spiesz ◽  
H.J.H. Brouwers
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete

scholarly journals Effects of Pumice-Based Porous Material on Hydration Characteristics and Persistent Shrinkage of Ultra-High Performance Concrete (UHPC)

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 11 ◽  
Author(s):  
Kaizhi Liu ◽  
Rui Yu ◽  
Zhonghe Shui ◽  
Xiaosheng Li ◽  
Xuan Ling ◽  
...  
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Energy Dispersive Spectrometer ◽  
Effective Area ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete ◽  
Composition And Structure ◽  
Different Diameters ◽  
Hydration Characteristics

In this paper, two kinds of pumice particles with different diameters and water absorption rates are employed to substitute the corresponding size of river sands by volume fraction, and their effects on the hydration characteristics and persistent shrinkage of Ultra-High Performance Concrete (UHPC) are investigated. The obtained experimental results show that adopting a low dosage of 0.6–1.25 mm saturated pumice as the internal curing agent in UHPC can effectively retract the persistent shrinkage deformation of concrete without a decrease of strength. Heat flow calorimetry results demonstrate that the additional water has a retarding effect and promotes the hydration process. X-ray Diffraction (XRD) and Differential Thermal Gravimetry (DTG) are utilized to quantify the Ca(OH)2 content in the hardened paste, which can confirm that the external moisture could accelerate the early cement hydration and secondary hydration of active mineral admixtures. The Ca/Si ratio of C–S–H calculated by the Energy Dispersive Spectrometer (EDS) reveals that the incorporation of wet pumice can transform the composition and structure of hydration products in its effective area.

Mechanical Properties and Durability of Ultra-High Performance Concrete Incorporating Coarse Aggregate

2014 ◽  
Vol 629-630 ◽  
pp. 96-103 ◽  
Author(s):  
Juan Yang ◽  
Gai Fei Peng ◽  
Yu Xin Gao ◽  
Hui Zhang
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Raw Materials ◽  
Autogenous Shrinkage ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete ◽  
Spalling Failure

Ultra-high performance concrete (UHPC) incorporating coarse aggregate was prepared with common raw materials. Fresh concrete had excellent good workability with slump of 265 mm and slump spread of 673 mm. Compressive strength of UHPC at 56 d reached 150 MPa. However, UHPC exhibited high brittleness in terms of spalling failure which occurred during compression loading.The ratio of splitting tensile strength to compressive strength of about 1/18 and the ratio of flexural strength to compressive strength of about 1/14 at 56 d were also associated with the brittleness of UHPC in this research. Mineral admixtures and fluidity of fresh concrete influenced compressive strength of UHPC significantly. Moreover, UHPC had excellent permeation-related durability but considerable shrinkage. Autogenous shrinkage of UHPC was less than half of free shrinkage, for which the reason is unknown and needs further research.

Preparation of Ultra-High Performance Concrete Using Phosphorous Slag Powder

2013 ◽  
Vol 357-360 ◽  
pp. 588-591 ◽  
Author(s):  
Yan Zhou Peng ◽  
Jin Huang ◽  
Jin Ke
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete ◽  
Slag Powder ◽  
Binder Ratio ◽  
Reactive Powder ◽  
Phosphorous Slag ◽  
Water Binder Ratio

Reactive powder concrete (RPC) is an ultra-high performance concrete (UHPC). Cement and silica fume content of RPC are generally rather high compared to the conventional concrete. The aim of this paper is to decrease the cement content of RPC by using phosphorous slag powder. Firstly the effect of grinding time on the activity index of phosphorous slag was investigated. And then, the mix proportion design of this UHPC containing phosphorous slag powder and silica fume was done through orthogonal design. The results indicate that the utilization of phosphorous slag powder in RPC is feasible when the dosage of phosphorous slag powder is about 35% (by weight of the binder) and the water-binder ratio is less than 0.18. By substituting phosphorous slag powder for a part of cement and keeping the water-binder ratio at about 0.14, UHPC specimens whose content of mineral admixtures, including phosphorous slag powder and silica fume, was about 40%~50% (by weight of the binder) were obtained after they had been cured in 80 °C water for 72 hours. The compressive and flexural strength of those specimens was more than 150 MPa and 20 MPa respectively.

Durability and Microstructure of Ultra-High Performance Concrete Having High Volume of Steel Slag Powder and Ultra-Fine Fly Ash

2011 ◽  
Vol 255-260 ◽  
pp. 452-456 ◽  
Author(s):  
Yan Zhou Peng ◽  
Kai Chen ◽  
Shu Guang Hu
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Mercury Porosimetry ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete ◽  
Slag Powder ◽  
Steel Slag Powder ◽  
Small Pore

The durability, such as chloride ion permeability, freeze-thaw and sulfate attack resistance of ultra-high performance concrete (UHPC) having a large amount, ranged from 42% to 48% by weight of binder, of mineral admixtures including steel slag powder (SS), ultrafine fly ash (UFFA) and silica fume (SF) was studied and the microstructure of selected UHPC compositions was investigated by Mercury porosimetry in this paper. Moreover, the relationship between durability and microstructure of UHPC was analyzed. The mercury porosimetry studies demonstrated the very low porosity and a high proportion of the innocuous pores as well as the very small pore size in UHPCs, whose most probable pore diameter did not exceed 10 nm. This porous structure of UHPCs would definitely enable the material have excellent durability.

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