Future Research Trends in High-Performance Concrete: Cost-Effective Considerations

1997 ◽  
Vol 1574 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Chao-Lung Hwang ◽  
Long-Sherng Lee
Keyword(s):  
Cycle Length ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Cost Effective ◽  
Research Trends ◽  
Future Research ◽  
Ongoing Research ◽  
Ordinary Concrete ◽  
High Rise

High-performance concrete (HPC) prepared on the basis of eugenic considerations (cost-effectiveness and life-cycle length) is proposed to resolve actual concrete problems. HPC is safe, durable, workable, economical, and ecologically sound. Concrete in Taiwan is always designed with large amounts of water and paste (even though it is generally accepted that the concrete will tend to crack and deteriorate). Therefore, HPC with fewer problems is the target of ongoing research. Eugenic HPC is produced from ordinary concrete, superplasticized concrete, pozzolanic concrete, and high-flowing concrete. Without the drawbacks of past forms of concrete, eugenic HPC is a better construction material on the basis of individual material characteristics. The characteristics of eugenic HPC are presented and illustrated by two high-rise buildings in Taiwan constructed with high-flowing HPC.

scholarly journals Materials for Production of High and Ultra-High Performance Concrete: Review and Perspective of Possible Novel Materials

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4304
Author(s):  
Markssuel Teixeira Marvila ◽  
Afonso Rangel Garcez de de Azevedo ◽  
Paulo R. de de Matos ◽  
Sergio Neves Monteiro ◽  
Carlos Maurício Fontes Vieira
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Review Article ◽  
Cement Matrix ◽  
Bibliographic Databases ◽  
Future Research ◽  
Chemical Additives ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Essential Components

This review article proposes the identification and basic concepts of materials that might be used for the production of high-performance concrete (HPC) and ultra-high-performance concrete (UHPC). Although other reviews have addressed this topic, the present work differs by presenting relevant aspects on possible materials applied in the production of HPC and UHPC. The main innovation of this review article is to identify the perspectives for new materials that can be considered in the production of novel special concretes. After consulting different bibliographic databases, some information related to ordinary Portland cement (OPC), mineral additions, aggregates, and chemical additives used for the production of HPC and UHPC were highlighted. Relevant information on the application of synthetic and natural fibers is also highlighted in association with a cement matrix of HPC and UHPC, forming composites with properties superior to conventional concrete used in civil construction. The article also presents some relevant characteristics for the application of HPC and UHPC produced with alkali-activated cement, an alternative binder to OPC produced through the reaction between two essential components: precursors and activators. Some information about the main types of precursors, subdivided into materials rich in aluminosilicates and rich in calcium, were also highlighted. Finally, suggestions for future work related to the application of HPC and UHPC are highlighted, guiding future research on this topic.

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.

scholarly journals Estimation of Super High-Rise Pumping Pressure for High-Performance Concrete Based on Computational Fluid Dynamics Modeling and Situation Measurement

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Weijiu Cui ◽  
Chuankai Zhao ◽  
Sheng Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Calculation Method ◽  
Pressure Loss ◽  
High Performance ◽  
High Performance Concrete ◽  
Accurate Method ◽  
Dynamics Modeling ◽  
High Rise ◽  
Pipe Line

Traditional methods fail to predict the pumping pressure loss of high-performance concrete properly in super high-rise pumping situations due to complex changes of concrete properties. Therefore, it is imperative to propose a relative accurate method for pumping pressure estimation in super high-rise buildings. This paper builds the simplified pressure calculation method “pressure induced by the gravity plus pressure along the pipe line.” The later one is gained by establishing topology optimized model based on computational fluid dynamics and considering the lubrication layer formation. The effect of rheological properties and flow rate is analyzed based on this model in detail. Furthermore, the developed calculation method is verified by the measured pumping pressure during the super high-rise building construction of the Shanghai Tower (the tallest building in China recently). The relative differences between the calculation results and the measured data in situ are less than 6%, indicating the applicability of this method for predicting the pressure loss of the super high-rise pumping.

Autogenous Shrinkage in Plain Cement Mixtures

2008 ◽  
Vol 400-402 ◽  
pp. 137-143 ◽  
Author(s):  
Vinod Rajayogan ◽  
Obada Kayali
Keyword(s):  
Experimental Determination ◽  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Basic Mechanism ◽  
Realistic Model ◽  
Test Method ◽  
Ongoing Research ◽  
Cement Mixtures

Determination of a realistic model for the estimation of autogenous shrinkage in plain cement mixtures has been an ongoing research among researchers in high performance concrete. While no standard test method exists for the determination of autogenous shrinkage, various researchers have designed different test methods for measurement of autogenous shrinkage. Current study involved the experimental determination of autogenous shrinkage using the test method developed by O.M.Jensen and co-workers, complimented with non-contact eddy current sensors. Measurements were conducted from as early as 1.5 hours from the time of casting. The samples were placed in a constant temperature chamber and the temperature of the sample was also monitored using a thermocouple. The study was carried out on plain cement mixtures at three water cement ratios of 0.25, 0.32 and 0.38. Measurements were also conducted on simple sealed prismatic samples but these measurements could only be collected after 24 hours of casting. The work is supplemented with CEMHYD3D simulations of the samples at similar water-cement ratios under sealed conditions so as to understand the development of the microstructure of the cement responsible for autogenous shrinkage. While experimental determination of internal relative humidity is quite difficult, data regarding chemical shrinkage, amount of water left and the development of the discontinuous capillary network from the simulations help to understand the determined experimental values of autogenous shrinkage. A detailed explanation on the causes of autogenous shrinkage and the basic mechanism responsible for it has been presented.

Optimization of Structural Design for High-Performance Concrete Bridges

1998 ◽  
Vol 1624 (1) ◽  
pp. 132-139
Author(s):  
Mary Lou Ralls ◽  
Ramon L. Carrasquillo ◽  
Ned H. Burns
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Cost Effective ◽  
Concrete Bridges ◽  
Practical Guidelines ◽  
Improved Performance ◽  
Maintenance Requirements ◽  
Design And Construction

High-performance concrete (HPC) bridges can be cost-effective both initially and in the long term, provided the design and construction optimize the improved performance characteristics of HPC. Using the high-strength characteristic of HPC can reduce the required number and size of beams. Using the improved durability characteristics of HPC can reduce maintenance requirements and extend the service life. Practical guidelines help design and construction engineers implement HPC in bridges.

scholarly journals Effect of Elevated Temperature on the Bond Strength of Prestressing Reinforcement in UHPC

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4990
Author(s):  
Petr Pokorný ◽  
Jiří Kolísko ◽  
David Čítek ◽  
Michaela Kostelecká
Keyword(s):  
Bond Strength ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Future Research ◽  
Ultra High Performance Concrete ◽  
Negative Effect ◽  
Laboratory Investigations ◽  
Increasing Temperature ◽  
Positive Effect

The study explores the effect of elevated temperatures on the bond strength between prestressing reinforcement and ultra-high performance concrete (UHPC). Laboratory investigations reveal that the changes in bond strength correspond well with the changes in compressive strength of UHPC and their correlation can be mathematically described. Exposition of specimens to temperatures up to 200 °C does not reduce bond strength as a negative effect of increasing temperature is outweighed by the positive effect of thermal increase on the reactivity of silica fume in UHPC mixture. Above 200 °C, bond strength significantly reduces; for instance, a decrease by about 70% is observed at 800 °C. The decreases in compressive and bond strengths for temperatures above 400 °C are related to the changes of phase composition of UHPC matrix (as revealed by X-ray powder diffraction) and the changes in microstructure including the increase of porosity (verified by mercury intrusion porosimetry and observation of confocal microscopy) and development cracks detected by scanning electron microscopy. Future research should investigate the effect of relaxation of prestressing reinforcement with increasing temperature on bond strength reduction by numerical modelling.

Advances in Research on Correlation of Workability and Rheology of Fresh Concrete: A Review

2009 ◽  
Vol 405-406 ◽  
pp. 77-82
Author(s):  
Gai Fei Peng ◽  
Zhan Qi Guo ◽  
Piet Stroeven ◽  
Ri Gao ◽  
Guang Hua Huang
Keyword(s):  
Literature Review ◽  
High Performance ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Experimental Tests ◽  
Test Method ◽  
Future Research ◽  
Specific Method ◽  
Self Compacting Concrete ◽  
The Relationship

A literature review was carried out to identify advances in research on workability of fresh concrete via both experimental tests and modeling, especially high performance concrete and self-compacting concrete. It is concluded that, in order to achieve better understanding of fresh concrete, especially self-compacting concrete (SCC) and high-performance concrete (HPC), a clear methodology of research should be established as the first step. It is suggested that there is no unique workability test method suitable for all the range of fluidity of fresh concrete, and a specific method should be identified for a proper range of fluidity. As to the relationship between fluidity of concrete and that of paste, future research can be conducted in two aspects, i.e. one is the influence of the quantity of paste in concrete, and another is the influence of fluidity of paste affected by a couple of factors.

Nonconventional Materials (NOCMAT) for Ecological and Sustainable Development

MRS Advances ◽  
2016 ◽  
Vol 1 (53) ◽  
pp. 3553-3564 ◽  
Author(s):  
Khosrow Ghavami ◽  
Arash Azadeh
Keyword(s):  
High Performance ◽  
Human Life ◽  
Natural Fibers ◽  
Construction Materials ◽  
Cost Effective ◽  
Ongoing Research ◽  
Vegetable Fibers ◽  
The People ◽  
Important Challenge

ABSTRACTFour decades of advanced research about Non-Conventional Materials and Technologies (NOCMAT) such as bamboo and composites reinforced with natural fibers have shown that it is now possible to produce and use high performance NOCMAT. Bamboo and composites reinforced with vegetable fibers are capable, meeting most engineering demand in terms of strength, stiffness, toughness and energy absorption capability. The greatest challenge of the 21st century is the need for cost-effective, durable and eco-friendly construction materials that will meet the global needs of infrastructure regeneration and rehabilitation which alone can enhance the quality of life for all the people of the world. This paper summarizes some results of judicious combination of different matrix reinforced with vegetable fibers, especially bamboo. These sustainable ecological materials are strong, ductile and capable of absorbing large amounts of energy. They could find extensive applications in the engineering particularly in developing countries. Specifically, the development of durable composites reinforced with vegetable fibers and bamboo poses an important challenge to the science and skills of engineering. This challenge could create the most useful, eco-friendly construction materials backed by an endless supply of renewable natural resources. In addition the paper presents results of some ongoing research concerning bamboo and how vegetable fibers such as hemp plant, before the invention of Nylon was the most used materials in all aspects of human life around the globe and why it was banned.

Technology of Ultra-High Strength / High Performance Concrete Applied to Guangzhou Xita Tower Construction

2009 ◽  
Vol 405-406 ◽  
pp. 1-4 ◽  
Author(s):  
Hao Wen Ye
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
High Strength ◽  
Hardened Concrete ◽  
High Rise ◽  
Slump Flow ◽  
Mix Proportion ◽  
New City ◽  
Pumping Equipment

This paper introduces development and application of ultra-high strength/high performance concrete in construction of the Xita tower high-rise building at Zhujiang New City of Guangzhou, China. The goal of the concrete construction in the Xita Tower project will be realized via research of mix proportion and optimization of pumping equipment. In regard to mix proportion of concrete, low water/cement (W/C) ratio, low water content lower than 150 kg/m3 and employment of superplasticizer are essential to acquire high strength. A series of parameters have been measured to research workability of concrete from C70 to C90, such slump, slump flow, flow time from inverted cone, L-box flow, and bleeding under pressure et al. Properties of hardened concrete should also be considered, including durability, autogenous shrinkage caused cracking, and fire resistance.

scholarly journals Mg-Li Hybrid Batteries: The Combination of Fast Kinetics and Reduced Overpotential

2022 ◽  
Vol 2022 ◽  
pp. 1-18
Author(s):  
Yajie Li ◽  
Yongjian Zheng ◽  
Kai Guo ◽  
Jingtai Zhao ◽  
Chilin Li
Keyword(s):  
High Performance ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Cost Effective ◽  
Material Design ◽  
High Volume ◽  
Future Research ◽  
Fast Kinetics ◽  
Interface Modification ◽  
Further Development

It is imperative for the development of cost-effective and high-performance batteries. Currently, lithium-ion batteries still occupy most of the market. However, limited lithium (Li) resource and energy density retard their further development. The magnesium (Mg) metal has several significant advantages; those make it a viable alternative to Li as anode, including high volume specific capacity and dendrite-free plating during cycling and high abundance. The Mg-Li hybrid batteries can combine the advantages of Li ion and Mg metal to achieve fast electrode kinetics and smooth anode deposition morphology. This review summarizes recent progresses in cathode material design and anode interface modification for Mg-Li hybrid batteries. We aim to illustrate the contribution of Li+ to the electrochemical performance improvement at both cathode and anode sides and to provide inspiration for the future research in this field.

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