scholarly journals Effects of Water Reducing Admixture on Rheological Properties, Fiber Distribution, and Mechanical Behavior of UHPFRC

2018 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Su-Tae Kang ◽  
Jae Kim ◽  
Bang Lee
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Distribution ◽  
Flexural Performance ◽  
Tensile Performance ◽  
High Performance Fiber ◽  
Hardened Properties

The rheological properties of ultra-high-performance fiber-reinforced concrete (UHPFRC) according to the amount of water reducing admixture (WRA) and their effects on the fiber distribution and the tensile performance of UHPFRC were investigated. Four types of mixtures with a high compressive strength over 150 MPa were designed according to the amount of WRA and the flowability, rheological properties, compressive strength, flexural performance, and fiber distribution were measured. Test results showed that the amount of WRA influences both the freshly mixed and hardened properties. It was also revealed that the flexural strength has a strong correlation with rheological properties, compressive strength, and fiber distribution.

Investigation of Properties of High-Performance Fiber-Reinforced Concrete: Very Early Strength, Toughness, Permeability, and Fiber Distribution

2017 ◽  
Vol 2629 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Evelina Khakimova ◽  
H. Celik Ozyildirim ◽  
Devin K. Harris
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Concrete Durability ◽  
Fiber Distribution ◽  
Fiber Reinforced ◽  
High Performance Fiber ◽  
Maintenance Work ◽  
Early Strength

Concrete cracking, high permeability, and leaking joints allow harmful solutions to intrude into concrete, resulting in concrete deterioration and corrosion of reinforcement. The development of durable concrete with limited cracking is a potential solution for extending the service life of concrete structures. Optimal design of very early strength (VES) durable materials will facilitate rapid and effective repairs and thus reduce traffic interruptions and maintenance work. The purpose of this study was to develop low-cracking durable materials that could achieve a very early compressive strength of 3,000 pounds per square inch within 10 h. Various proportions of silica fume, fly ash, steel fibers, and polypropylene fibers were used to evaluate concrete durability and postcracking performance. In addition, toughness, residual strength, permeability of cracked concrete, and fiber distribution were examined. VES durable concretes could be achieved with proper attention to mixture components (amounts of portland cement and accelerating admixtures), proportions (water–cementitious material ratio), and fresh concrete and curing temperatures. Permeability values indicated that minor increases in crack width, greater than 0.1 mm, greatly increased infiltration of solutions. Adding fibers could facilitate control of crack width. An investigation of fiber distribution showed preferential alignment and some clumping of fibers in the specimens and highlighted the need for sufficient mixing and proper sequencing of the addition of concrete ingredients into the mixer to ensure a uniform random fiber distribution. Results indicated that VES and durable fiber-reinforced concrete materials could be developed to improve the condition of existing and new structures and facilitate rapid, effective repairs and construction.

scholarly journals Effect of Tropical Climate Condition to Compressive Strength and Microstructure Properties of High Performance Fiber Reinforced Reinforced Concrete (HPFRC)

2015 ◽  
Vol 1115 ◽  
pp. 182-187 ◽  
Author(s):  
Siti Asmahani Saad ◽  
Farah Nora Aznieta Abdul Aziz ◽  
Maisarah Ali
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
Tropical Climate ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Climate Condition ◽  
Steam Curing ◽  
High Performance Fiber ◽  
Curing Method

Additional of fiber in concrete creates fiber reinforced concrete (FRC) with an improvement of the mechanical properties of the concrete. However, fiber incorporation in FRC is limited to 2% to allow normal mixing procedure. To address this issue, high performance fiber reinforced concrete (HPFRC) is introduced and it is relatively new in construction industry. Since very limited information on its capacity in tropical climate condition exposure, this research focuses on investigation of compressive strength and microstructure properties of the produced concrete in tropical climate condition. In order to complete this research, grade 80 cement slurry is used with 3%, 4% and 5% hooked-end steel fiber. Total numbers of 56 samples which are divided into 4 sets and exposed to two different curing methods namely water curing method and steam curing method at 80°C. Out of the 4 sets, 2 sets are exposed to tropical climate condition using climatic chamber at 80% relative humidity (RH) and constant temperature of 35°C for 30 days. Compression and ultrasonic pulse velocity (UPV) tests are carried out at 28 days to identify its strength as well as integrity of the concrete produced. Scanning electron microscopy (SEM) analysis is done to ascertain the microstructure properties of HPFRC. The highest compressive strength of 152.2 MPa was recorded for steam curing samples after exposed to tropical climate condition for 30 days with 5% steel fiber volume.

Effect of Density on Compressive Strength of Ultra High Performance Fiber Reinforced Concrete (UHPFRC) Using Design of Experiment

2016 ◽  
Vol 249 ◽  
pp. 119-124 ◽  
Author(s):  
Mohammad Ali Mosaberpanah ◽  
Ozgur Eren
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Design Of Experiment ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Fiber Reinforced Concrete ◽  
Ultra High Performance Concrete ◽  
Curing Conditions ◽  
High Performance Fiber

This paper aims to model the effect of density in 7, 14, 28 days on compressive strength of Ultra High Performance Concrete (UHPC) in same compaction and curing conditions by Design of Experiments (DOE) methodology using vary range of 5 variables: Silica fume (SF), Steel Fiber, Cement 42.5, Superplasticizer (SP), and water cemetiotious ratio (w/c).The results shows the significance effect of density on compressive strength of UHPC in different days, The models are valid for the mixes made with 1.0 sand, 0.15-0.30 silica fume amount, 0.70-1.30 cement amount, 0.10- 0.20 steel fiber, 0.04- 0.08 superplasticizer (all values are by sand by weight mass) and 0.18- 0.32 water cementitious ratio.

scholarly journals Flexural Behavior of Ultra-High Performance Fiber Reinforced Concrete Scale Tunnel Segment

2018 ◽  
Vol 38 ◽  
pp. 03037
Author(s):  
Kun Ni ◽  
Fa Sheng Zhang ◽  
Yun Xing Shi ◽  
Yan Gang Zhang ◽  
Jing Bin Shi
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Ultimate Load ◽  
Fiber Reinforced Concrete ◽  
Flexural Behavior ◽  
Fiber Reinforced ◽  
Flexural Performance ◽  
Four Point Bending ◽  
High Performance Fiber ◽  
Elastic Stage

To reduce the weight of precast tunnel segment, ultra-high performance fiber reinforced concrete (UHPFRC) was studied to cast the segment. The flexural performance of UHPFRC scale tunnel segments were tested in this work. The weight of the UHPFRC thinner scale tunnel segment was only 80% of reinforced concrete (RC) segment. The segments were loaded as per CJJ/T 164-2011, and the four-point bending system was used. The results showed that the cracking load increased 50%, and 0.2 mm crack width load increased 22%, and the yield load increased 11%, and the ultimate load only decreased 1%. The stiffness of elastic stage of UHPFRC segment looked the same compared to RC segment. In a word, the UHPFRC thinner segments showed excellent flexural performance beyond the traditional RC segment.

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