scholarly journals Use of Fiber Brag Gating Sensors in civil engineering applications

2021 ◽  
Author(s):  
Zahra Yazdizadeh
Keyword(s):  
High Performance ◽  
Civil Engineering ◽  
Prediction Models ◽  
High Performance Concrete ◽  
Shrinkage Strain ◽  
Second Phase ◽  
Engineering Applications ◽  
Fbg Sensors ◽  
Important Time ◽  
Creep And Shrinkage

This research presents an overview of development and application of Fiber Bragg Grating sensors (FBG) technology in civil engineering applications. The primary focus of this research is the use of FBGs to investigate two most important time-dependent properties of concrete namely: creep strain and shrinkage strain. The first phase of this investigation is focused on using FBG sensors to measure the concrete strains in unreinforced concrete beams and cylinders to determine modulus of elasticity, the modulus of rapture and fracture energy of concrete. The second phase of this research is designed to investigate the creep and shrinkage using FBG sensors. Normal strength concrete (NC), High performance concrete (HPC) and ultra-high performance (UHPC) specimens’ are used to measure creep and shrinkage strains and to compare the values with typical prediction models. The measured creep and shrinkage strains are compared to four different models to determine which model is the most accurate.

scholarly journals Use of Fiber Brag Gating Sensors in civil engineering applications

2021 ◽  
Author(s):  
Zahra Yazdizadeh
Keyword(s):  
High Performance ◽  
Civil Engineering ◽  
Prediction Models ◽  
High Performance Concrete ◽  
Shrinkage Strain ◽  
Second Phase ◽  
Engineering Applications ◽  
Fbg Sensors ◽  
Important Time ◽  
Creep And Shrinkage

This research presents an overview of development and application of Fiber Bragg Grating sensors (FBG) technology in civil engineering applications. The primary focus of this research is the use of FBGs to investigate two most important time-dependent properties of concrete namely: creep strain and shrinkage strain. The first phase of this investigation is focused on using FBG sensors to measure the concrete strains in unreinforced concrete beams and cylinders to determine modulus of elasticity, the modulus of rapture and fracture energy of concrete. The second phase of this research is designed to investigate the creep and shrinkage using FBG sensors. Normal strength concrete (NC), High performance concrete (HPC) and ultra-high performance (UHPC) specimens’ are used to measure creep and shrinkage strains and to compare the values with typical prediction models. The measured creep and shrinkage strains are compared to four different models to determine which model is the most accurate.

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.

scholarly journals REVIEW OF USE OF NANO MATERIAL IN MODIFYING THE PROPERTIES OF CONCRETE

2019 ◽  
Vol 4 ◽  
pp. 9
Author(s):  
Irfan U. Jan
Keyword(s):  
High Performance ◽  
Civil Engineering ◽  
High Performance Concrete ◽  
Biomedical Sciences ◽  
Concrete Technology ◽  
Nano Material ◽  
Promising Area ◽  
Active Research ◽  
Electronic Chemical ◽  
Modern Technologies

Modern technologies have affected all fields of human activities. Traditionally nanotechnologies deal with material having a dimension in the range of one billionth of a meter or 100 Nano meter in size. It has been widely used in natural sciences and biomedical sciences in the fields like microbiology, medicine, electronic, chemical, and materials sciences. The application of nontechnology and Nano material in Civil Engineering is still under active research in the areas of Concrete Technology, Construction management, water purification systems, Properties of Concrete at early ages and use of modern polymers in producing High Performance Concrete (HPC). The use of Nano material to produce relatively sustainable concrete represents a promising area of research in Nano material. In this paper the State of the Art of application of Nanotechnologies to Civil Engineering and its future prospects with special reference to sustainability in construction.

Macroscopic and Microscopic Properties of High Performance Concrete with Partial Replacement of Cement by Fly Ash

2019 ◽  
Vol 292 ◽  
pp. 108-113 ◽  
Author(s):  
Josef Fládr ◽  
Petr Bílý ◽  
Roman Chylík ◽  
Zdeněk Prošek
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Partial Replacement ◽  
Experimental Program ◽  
Second Phase ◽  
Depth Of Penetration ◽  
Cement Replacement

The paper describes an experimental program focused on the research of high performance concrete with partial replacement of cement by fly ash. Four mixtures were investigated: reference mixture and mixtures with 10 %, 20 % and 30 % cement weight replaced by fly ash. In the first stage, the effect of cement replacement was observed. The second phase aimed at the influence of homogenization process for the selected 30% replacement on concrete properties. The analysis of macroscopic properties followed compressive strength, elastic modulus and depth of penetration of water under pressure. Microscopic analysis concentrated on the study of elastic modulus, porosity and mineralogical composition of cement matrix using scanning electron microscopy, spectral analysis and nanoindentation. The macroscopic results showed that the replacement of cement by fly ash notably improved compressive strength of concrete and significantly decreased the depth of penetration of water under pressure, while the improvement rate increased with increasing cement replacement (strength improved by 18 %, depth of penetration by 95 % at 30% replacement). Static elastic modulus was practically unaffected. Microscopic investigation showed impact of fly ash on both structure and phase mechanical performance of the material.

Structural Design of High-Performance Concrete Bridge Beams

2000 ◽  
Vol 1696 (1) ◽  
pp. 171-178
Author(s):  
Xiaoming (Sharon) Huo ◽  
Maher K. Tadros
Keyword(s):  
Structural Design ◽  
High Performance ◽  
High Performance Concrete ◽  
Highway Bridges ◽  
Major Effect ◽  
Minor Effect ◽  
Bottom Flange ◽  
Prestress Losses ◽  
Bridge Beams ◽  
Creep And Shrinkage

Recently high-performance concrete (HPC) has been used in highway bridges and has gained popularity for its short-term and prospective long-term performances. Benefits of using HPC include fewer girder lines required, longer span capacity of girders, reduced creep and shrinkage deformation, less prestress losses, longer life cycle, and less maintenance of bridges. Research has been conducted on several issues of structural design of HPC bridge beams. The topics discussed include the effects of section properties of prestressed concrete girders, allowable tensile and compressive stresses, creep and shrinkage deformations of HPC, and prediction of prestress losses with HPC. The results from a parametric study have shown that a section that can have a large number of strands placed in its bottom flange is more suitable for HPC applications. The use of 15-mm-diameter prestressing strands allows the higher prestressing force applied on sections and can provide more efficiency in HPC bridges. The research results also indicate that the allowable compressive strength of HPC has a major effect on the structural design of bridges, whereas the allowable tensile stress has a minor effect on the design. Equations for predicting prestress losses based on the experimental and analytical results are recommended. The recommended equations consider the effects of lower creep and shrinkage deformations of HPC.

Sign in / Sign up

Export Citation Format

Share Document