scholarly journals The Influence of Selected Material and Technological Factors on Mechanical Properties and Microstructure of Reactive Powder Concrete (RPC) / Wpływ Wybranych Czynników Materiałowych I Technologicznych Na Własciwosci Mechaniczne I Mikrostrukture Betonów Z Proszków Reaktywnych (BPR)

2011 ◽  
Vol 57 (2) ◽  
pp. 227-246 ◽  
Author(s):  
T. Zdeb ◽  
J. Sliwinski
Keyword(s):  
Bending Test ◽  
Reactive Powder Concrete ◽  
Test Load ◽  
Curing Conditions ◽  
Steel Fibres ◽  
Three Point Bending ◽  
Technological Factors ◽  
University Of Technology ◽  
Reactive Powder ◽  
Work Of Fracture

Abstract The paper deals with the properties and microstructure of Reactive Powder Concrete (RPC), which was developed at Cracow University of Technology. The influence of three different curing conditions: water (W), steam (S) and autoclave (A) and also steel fibres content on selected properties of RPC was analyzed. The composite characterized by w/s ratio equal to 0.20 and silica fume to cement ratio 20%, depending on curing conditions and fibres content, obtained compressive strength was in the range from 200 to 315 MPa, while modulus of elasticity determined during compression was about 50 GPa. During three-point bending test load-deflection curves were registered. Base on aforementioned measurements following parameters were calculated: flexural strength, stress at limit of proportionality (LOP), stress at modulus of rapture (MOR), work of fracture (WF), and toughness indices I5, I10 and I20. Both amount of steel fibres and curing conditions influence the deflection of RPC during bending.

Effects of Curing Systems on the Strength and Microstructure of Reactive Powder Concrete with Iron Tailing Sands

2014 ◽  
Vol 548-549 ◽  
pp. 247-253
Author(s):  
Zhi Gang Zhu ◽  
Bei Xing Li ◽  
Jin Cheng Liu ◽  
Xing Dong Lv
Keyword(s):  
Point Of View ◽  
Hot Water ◽  
Curing Temperature ◽  
Reactive Powder Concrete ◽  
Curing Time ◽  
Submicroscopic Structure ◽  
Curing Conditions ◽  
The Difference ◽  
Reactive Powder ◽  
Curing Systems

To produce 130MPa reactive powder concrete with iron tailing sands as aggregation in an economic hot curing system, the effects of curing temperature, curing time and curing conditions on the reactive powder concrete was studied, the reasons of the strength of reactive powder concrete in different curing systems has the difference from the submicroscopic structure point of view was analyzed. The results show that use 90°C hot water to cure reactive powder concrete for 48h can lead it’s 28 day compressive strength reaches 140MPa, the flexural strength reaches 28MPa.

scholarly journals Effect of different curing conditions on the mechanical properties of reactive powder concrete

2018 ◽  
Vol 162 ◽  
pp. 02014
Author(s):  
Mazin Abdulrahman ◽  
Alyaa Al-Attar ◽  
Marwa Ahmad
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Material Constant ◽  
Hot Water ◽  
Modulus Of Rupture ◽  
Reactive Powder Concrete ◽  
Curing Conditions ◽  
Reactive Powder

Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanical and physical properties, and composed of cement and very fine powders such as quartz sand and silica fume with very low water/ binder ratio and Superplasticizer. Heat treatment is a well-known method that can further improve the performance of (RPC). The current research including an experimental study of the effect of different curing conditions on mechanical properties of reactive powder concrete (compressive strength, modulus of rupture and splitting tensile strength), the curing conditions includes three type of curing; immersion in water at temperature of 35 OC (which is considered as the reference-curing situation), immersion in water at temperature of 90 OC for 5 hours daily and curing with hot steam for 5 hours daily) until 28 days according to ASTM C684-99 [8]. This research includes also the study of effect of adding silica fume as percentage of cement weight on mechanical properties of reactive powder concrete for different percentage ratios (5%,10% and 15%). Super plasticizer is also used with ratio of (1.8%) by weight of cementitious material; constant water cement ratio (0.24) was used for all mixes. For each reactive concrete mix, it has been cast into a cubes of (150*150*150) (to conduct the compression test), a cylinders of 150mm diameter with 300mm height (to conduct split test) and prisms of (500*100*100)mm to conduct the modulus of rupture test. The results showed that the best method of curing (according to its enhancing the RPC mechanical properties) is the method of immersion in hot water at temperature 90 OC for the all silica fume percentages, and the best used silica fume percentage was (10%) for the all used curing methods.

scholarly journals Bending Resistance and Failure Type Evaluation of Basalt Fiber RPC Beam Affected by Notch and Interfacial Damage Using Acoustic Emission

2020 ◽  
Vol 10 (3) ◽  
pp. 1138 ◽  
Author(s):  
Hanbing Liu ◽  
Xiang Lyu ◽  
Yuwei Zhang ◽  
Guobao Luo ◽  
Wenjun Li
Keyword(s):  
Acoustic Emission ◽  
Basalt Fiber ◽  
Steel Fibers ◽  
Bending Test ◽  
Reactive Powder Concrete ◽  
Basalt Fibers ◽  
Interfacial Damage ◽  
Failure Type ◽  
Bending Resistance ◽  
Reactive Powder

Generally, reactive powder concrete (RPC) contains steel fibers often exposed to aggressive environments. Steel fibers in such RPCs are subjected to corrosion in-service, which can significantly change the mechanical properties of the structural components. In this paper, basalt fibers were used to replace steel fibers for preparing a new basalt fiber modified reactive powder concrete (BFRPC). The bending resistance of BFRPC beams was studied, and the crack propagation and failure type of BFRPC beam were monitored by acoustic emission (AE). During the bending test, the failure type of BFRPC was evaluated by AE. Besides, the effects of notch and interfacial damage on the bending resistance and failure type were also studied. During the test, ordinary Reactive Powder Concrete (RPC) without basalt fibers was used as a reference. Results revealed that failure type of the RPC beam and BFRPC beam was mainly caused by shear failure. The notch increased the number of tensile cracks in the beam failure crack, resulting in a decrease in the bending resistance of RPC beam and BFRPC beam. Besides, basalt fiber could improve the toughness and bending resistance of BFRPC beam and increase resistance of the BFRPC beam to notch and interface damage.

scholarly journals Flexural Strength and Acoustic Damage Characteristics of Steel Bar Reactive Powder Concrete

2021 ◽  
Vol 11 (15) ◽  
pp. 7017
Author(s):  
Tingyou Yi ◽  
Hua Wang ◽  
Juntao Xie ◽  
Wensheng Wang
Keyword(s):  
Flexural Strength ◽  
Fracture Process ◽  
Average Frequency ◽  
Bending Test ◽  
Reactive Powder Concrete ◽  
Shear Cracks ◽  
Tensile Cracks ◽  
Steel Bar ◽  
Steel Bars ◽  
Reactive Powder

In this paper, the steel bar was used to prepare steel bar reactive powder concrete (SBRPC). The three-point bending test was adopted to investigate the effect of the number of steel bars on the flexural strength of SBRPC. The acoustic emission (AE) was used to monitor the fracture process of SBRPC in real time. In addition, the parameter RA and AF ratio (RF) was defined to analyze the distribution of shear cracks and tensile cracks during the fracture process. The experimental results showed that with the increases in the number of the steel bar, the flexural strength of SBRPC gradually increased. The fracture stage of SBRPC can be accurately divided according to the curve slope change in hits and cumulative counts. Moreover, the early warning of SBRPC damage can be realized by observing the amplitude of the AE amplitude value. The dynamic changes in the rising angle (RA) and average frequency (AF) values can be used to determine the cracks mode and fracture mode. Based on the results of RF analysis, adding steel bars will improve the proportion for tensile cracks during its fracture process.

Alkali Activated Binders Based Concrete Specimens: Length Change and Fracture Tests

2016 ◽  
Vol 258 ◽  
pp. 623-626 ◽  
Author(s):  
Vlastimil Bílek Jr. ◽  
Hana Šimonová ◽  
Ivana Havlíková ◽  
Libor Topolář ◽  
Barbara Kucharczyková ◽  
...  
Keyword(s):  
Stress Concentrator ◽  
Length Change ◽  
Bending Test ◽  
Crack Model ◽  
Mechanical Fracture ◽  
Three Point Bending ◽  
Fracture Tests ◽  
Alkali Activated Binders ◽  
Work Of Fracture ◽  
Alkali Activated

The aim of this paper is to quantify mechanical fracture and length change parameters of the two types of concrete with alkali activated binder. The six beam specimens (75 × 75 × 295 mm) were made from each mixture. After demolding specimens were placed in air storage for 28 days. During this period length change (shrinkage) were recorded in accordance with ASTM C490 (2011). After that the three-point bending test was performed on these specimens with initial stress concentrator at the age of 28 days to obtain the mechanical fracture parameters. Records of fracture tests in form load versus deflection (F–d) diagrams were evaluated using effective crack model and work of fracture method.

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