scholarly journals Development of Engineered Cementitious Composites Using Sea Sand and Metakaolin

2021 ◽  
Vol 8 ◽  
Author(s):  
Qiyao Yao ◽  
Zuo Li ◽  
Chenyu Lu ◽  
Linxin Peng ◽  
Yuejing Luo ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fracture Energy ◽  
Tensile Strain ◽  
Chloride Ions ◽  
Silica Sand ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites ◽  
Strain Capacity ◽  
Sea Sand ◽  
Tensile Strain Capacity

The present study investigates the possibility of using sea sand, instead of silica sand, in producing engineered cementitious composites (ECCs) and the optimal mix proportion, mechanical behavior, and erosive effect of chloride ions on sea sand ECCs (SECCs). Nine groups of SECC specimens were prepared based on the orthogonal test design, and these cured for the uniaxial tensile, uniaxial compression, and fracture energy tests. The roundness and sphericity of sea sand and silica sand were quantified by digital microscopy. The microstructure and composition of SECCs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mix proportions of SECCs with a tensile strain capacity more than 2% and a compressive strength more than 60 MPa were obtained. The factor analysis of these serial tests revealed that the contents of both fly ash and sea sand have a significant effect on the compressive strength and tensile strain capacity of SECCs. The fracture energy test revealed that the matrix fracture toughness of SECCs significantly increases with the increase in sea sand content. The XRD analysis revealed that the addition of metakaolin can enhance the ability of SECCs to bind chloride ions, and with the increase in chloride ion content, the ability of SECCs to bind chloride ions would improve. The results of the present study provide further evidence of the feasibility of using sea sand in the production of ECCs, in order to meet the requirements of diverse concrete components on ductility and durability.

scholarly journals Recent Advances in Strain-Hardening UHPC with Synthetic Fibers

2021 ◽  
Vol 5 (10) ◽  
pp. 283
Author(s):  
Jian-Guo Dai ◽  
Bo-Tao Huang ◽  
Surendra P. Shah
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Strain Hardening ◽  
Crack Width ◽  
Tensile Strain ◽  
Cumulative Probability ◽  
Strain Capacity ◽  
Synthetic Fibers ◽  
Recent Advances ◽  
Tensile Strain Capacity

This paper summarizes recent advances in strain-hardening ultra-high-performance concretes (UHPC) with synthetic fibers, with emphasis on their tensile properties. The composites described here usually contain about 2.0% high-density polyethylene (PE) fibers. Compared to UHPC with steel fibers, strain-hardening UHPC with synthetic fibers generally show a higher tensile ductility, lower modulus in the cracked state, and relatively lower compressive strength. The tensile strain capacity of strain-hardening UHPC with synthetic fibers increases with increasing tensile strength. The f’cftεt/w index (compressive strength × tensile strength × tensile strain capacity/tensile crack width) is used to compare the overall performance of strain-hardening UHPC. Moreover, a probabilistic approach is applied to model the crack width distributions of strain-hardening UHPC, and estimate the critical tensile strain in practical applications, given a specific crack width limit and cumulative probability. Recent development on strain-hardening UHPC with the use of seawater, sea-sand and PE fibers are also presented.

scholarly journals Development of Ultra-Lightweight and High Strength Engineered Cementitious Composites

2021 ◽  
Vol 5 (4) ◽  
pp. 113
Author(s):  
Zhitao Chen ◽  
Junxia Li ◽  
En-Hua Yang
Keyword(s):  
Tensile Strain ◽  
High Strength ◽  
Matrix Composition ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites ◽  
Micromechanical Properties ◽  
Matrix Fracture ◽  
The Matrix ◽  
Lightweight Filler ◽  
Tensile Strain Capacity

In this study, ultra-lightweight and high strength Engineered Cementitious Composites (ULHS-ECCs) are developed via lightweight filler incorporation and matrix composition tailoring. The mechanical, physical, and micromechanical properties of the resulting ULHS-ECCs are investigated and discussed. ULHS-ECCs with a density below 1300 kg/m3, a compressive strength beyond 60 MPa, a tensile strain capacity above 1%, and a thermal conductivity below 0.5 w/mK are developed. The inclusion of lightweight fillers and the variation in proportioning of the ternary binder can lead to a change in micromechanical properties, including the matrix fracture toughness and the fiber/matrix interface properties. As a result, the tensile strain-hardening performance of the ULHS-ECCs can be altered.

scholarly journals Strain-Hardening and High-Ductile Behavior of Alkali-Activated Slag-Based Composites with Added Zirconia Silica Fume

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3523 ◽  
Author(s):  
Jeong-Il Choi ◽  
Se-Eon Park ◽  
Huy Hoàng Nguyễn ◽  
Sang Lyul Cha ◽  
Bang Yeon Lee
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Silica Fume ◽  
Tensile Strain ◽  
Alkali Activated Slag ◽  
Strain Capacity ◽  
Activated Slag ◽  
Ductile Behavior ◽  
Tensile Strain Capacity ◽  
Alkali Activated

This paper presents an experimental study on the effects of zirconia silica fume on the composite properties and cracking patterns of fiber-reinforced alkali-activated slag-based composites. Four mixtures were prepared with added zirconia silica fume and varying water-to-binder ratio. Polyethylene fiber was used as a reinforcing fiber for all the mixtures at a volumetric ratio of 2.0% cubic specimens and uniaxial tensile specimens were prepared to evaluate their density, compressive strength, and tensile behavior. The test results demonstrated that the compressive strength, tensile strength, and tensile strain capacity of the composite can be simultaneously improved by incorporating zirconia silica fume. A mixture incorporating zirconia silica fume showed high-ductile behavior of 26.5% higher tensile strength, and 13.7% higher tensile strain capacity than the mixture without zirconia silica fume. The composite with added zirconia silica fume also showed excellent cracking patterns, i.e., narrow crack spacing and crack width.

Multi-Tier Tensile Strain Models for Strain-Based Design: Part 2 — Development and Formulation of Tensile Strain Capacity Models

2012 ◽  
Author(s):  
Ming Liu ◽  
Yong-Yi Wang ◽  
Yaxin Song ◽  
David Horsley ◽  
Steve Nanney
Keyword(s):  
Driving Force ◽  
Tensile Strain ◽  
Weld Strength ◽  
Experiment Data ◽  
Pipe Wall Thickness ◽  
Crack Driving Force ◽  
Strain Capacity ◽  
Welding Processes ◽  
Tensile Strain Capacity

This is the second paper in a three-paper series related to the development of tensile strain models. The fundamental basis of the models [1] and evaluation of the models against experiment data [2] are presented in two companion papers. This paper presents the structure and formulation of the models. The philosophy and development of the multi-tier tensile strain models are described. The tensile strain models are applicable for linepipe grades from X65 to X100 and two welding processes, i.e., mechanized GMAW and FCAW/SMAW. The tensile strain capacity (TSC) is given as a function of key material properties and weld and flaw geometric parameters, including pipe wall thickness, girth weld high-low misalignment, pipe strain hardening (Y/T ratio), weld strength mismatch, girth weld flaw size, toughness, and internal pressure. Two essential parts of the tensile strain models are the crack driving force and material’s toughness. This paper covers principally the crack driving force. The significance and determination of material’s toughness are covered in the companion papers [1,2].

Estimation of Tensile Strain Capacity of Vintage Girth Welds

2021 ◽  
Author(s):  
Banglin Liu ◽  
Bo Wang ◽  
Yong-Yi Wang ◽  
Otto Jan Huising
Keyword(s):  
Tensile Strain ◽  
Strain Capacity ◽  
Girth Welds ◽  
Tensile Strain Capacity
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