scholarly journals High-Durability Concrete Using Eco-Friendly Slag-Pozzolanic Cements and Recycled Aggregate

2020 ◽  
Vol 10 (22) ◽  
pp. 8307
Author(s):  
Klaus Voit ◽  
Oliver Zeman ◽  
Ivan Janotka ◽  
Renata Adamcova ◽  
Konrad Bergmeister
Keyword(s):  
Environmental Sustainability ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Materials ◽  
Recycled Aggregate ◽  
Basic Material ◽  
Infrastructure Development ◽  
High Durability ◽  
Pozzolanic Cement ◽  
Carbon Dioxide Co2

Clinker production is very energy-intensive and responsible for releasing climate-relevant carbon dioxide (CO2) into the atmosphere, and the exploitation of aggregate for concrete results in a reduction in natural resources. This contrasts with infrastructure development, surging urbanization, and the demand for construction materials with increasing requirements in terms of durability and strength. A possible answer to this is eco-efficient, high-performance concrete. This article illustrates basic material investigations to both, using eco-friendly cement and recycled aggregate from tunneling to produce structural concrete and inner shell concrete, showing high impermeability and durability. By replacing energy- and CO2-intensive cement types by slag-pozzolanic cement (CEM V) and using recycled aggregate, a significant contribution to environmental sustainability can be provided while still meeting the material requirements to achieve a service lifetime for the tunnel structure of up to 200 years. Results of this research show that alternative cements (CEM V), as well as processed tunnel spoil, indicate good applicability in terms of their properties. Despite the substitution of conventional clinker and conventional aggregate, the concrete shows good workability and promising durability in conjunction with adequate concrete strengths.

scholarly journals Sulfate Resistance of Recycled Aggregate Concrete with GGBS and Fly Ash-Based Geopolymer

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1247 ◽  
Author(s):  
Jianhe Xie ◽  
Jianbai Zhao ◽  
Junjie Wang ◽  
Chonghao Wang ◽  
Peiyan Huang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Construction Projects ◽  
High Performance ◽  
High Performance Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Sulfate Resistance ◽  
Coarse Aggregates

There is a constant drive for the development of ultra-high-performance concrete using modern green engineering technologies. These concretes have to exhibit enhanced durability and incorporate energy-saving and environment-friendly functions. The object of this work was to develop a green concrete with an improved sulfate resistance. In this new type of concrete, recycled aggregates from construction and demolition (C&D) waste were used as coarse aggregates, and granulated blast furnace slag (GGBS) and fly ash-based geopolymer were used to totally replace the cement in concrete. This study focused on the sulfate resistance of this geopolymer recycled aggregate concrete (GRAC). A series of measurements including compression, X-ray diffraction (XRD), and scanning electron microscopy (SEM) tests were conducted to investigate the physical properties and hydration mechanisms of the GRAC after different exposure cycles in a sulfate environment. The results indicate that the GRAC with a higher content of GGBS had a lower mass loss and a higher residual compressive strength after the sulfate exposure. The proposed GRACs, showing an excellent sulfate resistance, can be used in construction projects in sulfate environments and hence can reduce the need for cement as well as the disposal of C&D wastes.

Roof Structural System Study with Use of UHPC

2017 ◽  
Vol 259 ◽  
pp. 70-74
Author(s):  
Milan Holý
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Structural System ◽  
Total Load ◽  
Dominant Component ◽  
Industrial Buildings ◽  
Normal Strength ◽  
Very High

This paper deals with the roof structural system using prestressed girders made of ultra-high performance concrete (UHPC). One of the aims of this study is to verify whether the option of the UHPC girders could be under certain boundary conditions competitive with the commonly used construction materials. Due to its high strength, UHPC enables the design of the structural elements with the high load bearing capacity and with smaller slenderness compared to normal strength concrete elements. The price of UHPC is currently still very high compared to the normal strength concretes or steel. Therefore, its use for the usual designed structures does not recently seem too economically attractive. The effect of material savings is nonnegligible in the case, that a self-weight of the structure forms dominant component of the total load. In addition to the high strength, UHPC has very high resistance to environmental influences. It is therefore likely, that UHPC could be advantageously applied e.g. for the roofing of industrial buildings of chemical plants with high aggressive environments, because there are high demands on the life cycle of the structure.

scholarly journals Experimental Characterization of Prefabricated Bridge Deck Panels Prepared with Prestressed and Sustainable Ultra-High Performance Concrete

2020 ◽  
Vol 10 (15) ◽  
pp. 5132
Author(s):  
Muhammad Naveed Zafar ◽  
Muhammad Azhar Saleem ◽  
Jun Xia ◽  
Muhammad Mazhar Saleem
Keyword(s):  
High Performance ◽  
Bridge Deck ◽  
High Performance Concrete ◽  
High Strength ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Ultra High Performance Concrete ◽  
Aggregate Concrete ◽  
Deck Panels

Enhanced quality and reduced on-site construction time are the basic features of prefabricated bridge elements and systems. Prefabricated lightweight bridge decks have already started finding their place in accelerated bridge construction (ABC). Therefore, the development of deck panels using high strength and high performance concrete has become an active area of research. Further optimization in such deck systems is possible using prestressing or replacement of raw materials with sustainable and recyclable materials. This research involves experimental evaluation of six full-depth precast prestressed high strength fiber-reinforced concrete (HSFRC) and six partial-depth sustainable ultra-high performance concrete (sUHPC) composite bridge deck panels. The composite panels comprise UHPC prepared with ground granulated blast furnace slag (GGBS) with the replacement of 30% cement content overlaid by recycled aggregate concrete made with replacement of 30% of coarse aggregates with recycled aggregates. The experimental variables for six HSFRC panels were depth, level of prestressing, and shear reinforcement. The six sUHPC panels were prepared with different shear and flexural reinforcements and sUHPC-normal/recycled aggregate concrete interface. Experimental results exhibit the promise of both systems to serve as an alternative to conventional bridge deck systems.

Green High Performance Concrete Based on Sustainable Development

2014 ◽  
Vol 584-586 ◽  
pp. 1568-1572
Author(s):  
Ping Zhang ◽  
Ying Cao
Keyword(s):  
Sustainable Development ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Materials ◽  
Living Environment ◽  
The Sustainable Development ◽  
Green Concrete ◽  
Concrete Production ◽  
Concrete Materials ◽  
The Relationship

Green high performance concrete is concrete materials which can reduce the load of the earth's environment, coordinate development with the ecosystem and create comfortable living environment. The relationship between the construction materials and the sustainable development and the characteristic of green high performance concrete were introduced, the measures of green concrete production was analyzed and the work essential for the development of green high performance concrete was proposed in this paper. The research shows that the development of green high performance concrete is the inevitable way for the sustainable development of concrete.

Analysis of Microstructure of Interfacial Transition Zone (ITZ) in Recycled Aggregate Concrete

2013 ◽  
Vol 811 ◽  
pp. 249-253 ◽  
Author(s):  
Wei Li ◽  
Hai Ying Zhang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Interfacial Structure ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Interfacial Zone ◽  
Aggregate Concrete ◽  
Mortar Strength

Experiments on influence of species of aggregate and mixing method on interfacial zone in recycled aggregate concrete were investigated. SEM observations revealed that a recycle normal-strength concrete aggregate consist of loose and porous interfacial structure, whereas a recycled high performance concrete (HPC) aggregate and a triple mixing (TM) consist mainly of dense hydrates. Various admixtures on ITZ was produced that consumed CH in the pore, modified attached cement mortar. Strength of recycled concrete was explained by interaction between cements paste and recycled aggregate. The result verified that the relatively dense pore structure of the recycled concrete benefit to development of mechanical properties.

Fresh Properties of Mortar made with Pozzolanic Cement and Water Reducers

2012 ◽  
Vol 1488 ◽  
Author(s):  
María E. Sosa ◽  
Yury A. Villagrán-Zaccardi ◽  
Claudio J. Zega ◽  
P.Peralta Juan
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Practical Implication ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Surface Finishing ◽  
Main Role ◽  
Natural Pozzolans ◽  
Different Types ◽  
Pozzolanic Cement

ABSTRACTNatural pozzolans are supplementary cementitious materials (SCMs) that may be used to improve the properties of mortar and concrete, through the formation of additional hydration products by pozzolanic action. Water reducers (WR) play a main role in high performance concrete in terms of durability, strength and surface finishing. A first optimization of constituent proportions in paste and/or mortar is convenient to assess the compatibility between the WR and the cementitious materials. The compatibility between cement and WR may be affected by SCMs, as they can also interact with the molecules of the admixture. However, the practical implication may be variable. This paper deals with the influence of different types and dosages of WRs in mortars made with pozzolanic Portland cement. Both medium and high ranges WRs have been used. Mortar fluidity has been tested by the spread and the slump tests. Results show different fluidizing capacities of WRs, among which polycarboxylate-based WR was the most compatible with the pozzolanic cement.

scholarly journals The Impact of Nano Clay on Normal and High-Performance Concrete Characteristics: A Review

2022 ◽  
Vol 961 (1) ◽  
pp. 012085
Author(s):  
Aseel Mansi ◽  
Nadhim Hamah Sor ◽  
Nahla Hilal ◽  
Shaker M A Qaidi
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Construction Materials ◽  
Sulfate Attack ◽  
Review Article ◽  
Nucleation Sites ◽  
Nano Clay ◽  
The Impact

Abstract The use of nano clay to improve the qualities of construction materials and engineering applications has attracted a lot of discussion in recent years. This review article summarizes the influence of nano clay as a cement substitute and supplement on the performance of conventional and high-performance concrete. The addition of nano clay to high performance concrete revealed an increase in compressive and flexural strength, as well as durability attributes such as resistance to elevated temperatures and sulfate attack, while simultaneously decreasing porosity, permeability, and water absorption. This enhancement is a result of nano clay’s roles as nano reinforcements, nanofillers, nucleation sites, and reactive pozzolans, which promote hydration and increase material characteristics.

scholarly journals The Utilization of Recycled Aggregate in High Performance Concrete: A Review

2020 ◽  
Vol 9 (4) ◽  
pp. 8469-8481 ◽  
Author(s):  
Bassam A. Tayeh ◽  
Doha M. Al Saffar ◽  
Rayed Alyousef
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Recycled Aggregate

Microstructural Features of Recycled Aggregate Concrete: From Non-Structural to High-Performance Concrete

2019 ◽  
Vol 25 (3) ◽  
pp. 601-616 ◽  
Author(s):  
Diogo Pedro ◽  
Mafalda Guedes ◽  
Jorge de Brito ◽  
Luís Evangelista
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Sequential Approach

AbstractThe use of concrete-recycled aggregates to produce high-performance concrete is limited by insufficient correlation between resulting microstructure and its influence on mechanical performance reproducibility. This work addresses this issue in a sequential approach: concrete microstructure was systematically analyzed and characterized by scanning electron microscopy and results were correlated with concrete compressive strength and water absorption ability. The influence of replacing natural aggregates (NA) with recycled concrete aggregates (RCA), with different source concrete strength levels, of silica fume (SF) addition and of mixing procedure was tested. The results show that the developed microstructure depends on the concrete composition and is conditioned by the distinct nature of NA, recycled aggregates from high-strength source concrete, and recycled aggregates from low-strength source concrete. SF was only effective at concrete densification when a two-stage mixing approach was used. The highest achieved strength in concrete with 100% incorporation of RCA was 97.3 MPa, comparable to that of conventional high-strength concrete with NA. This shows that incorporation of significant amounts of RCA replacing NA in concrete is not only a realistic approach to current environmental goals, but also a viable route for the production of high-performance concrete.

UHPC Footbridge over the Opatovický Canal

2016 ◽  
Vol 249 ◽  
pp. 320-324
Author(s):  
Jan Tichý ◽  
David Čítek ◽  
Jiří Kolísko ◽  
Jan Komanec ◽  
Bohuslav Slánský ◽  
...  
Keyword(s):  
Material Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Cementitious Material ◽  
Ultra High Performance Concrete ◽  
High Durability ◽  
Design Production ◽  
New Type ◽  
Reliable Design

Article deals with design of footbridge made from ultra high performance concrete (UHPC). UHPC is relatively new type of cementitious material with high compressive strength and high durability. For reliable design of construction from this material an extensive experimental research and verification of material properties are needed. Skanska and Pontex company with cooperation with Klokner institute developed matrix of UHPC used for footbridge construction. Material properties were verified during whole developing and producing process. Footbridge was casted in precast plant Skanska – Steti in December 2014. It was installed over Opatovický canal in October 2015. Contribution describes design, production and installation of footbridge. Material properties of used UHPC are also included.

Sign in / Sign up

Export Citation Format

Share Document