scholarly journals Correlations Among Various Self-Consolidating Concrete Workability Responses

2012 ◽  
Vol 6 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Wu-Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
Mechanical Vibration ◽  
Maximum Size ◽  
Test Methods ◽  
Test Results ◽  
Testing Methods ◽  
Self Consolidating Concrete ◽  
Filling Ability ◽  
Crushed Aggregate ◽  
Class F Fly Ash ◽  
Passing Ability

Self-consolidating concrete (SCC) mixtures designated for precast, prestressed applications should be highly workable to flow easily through restricted spacing and completely encapsulate reinforcements without any mechanical vibration. Key workability characteristics of SCC can be described in terms of filling ability, passing ability, and resistance to segregation. These properties are typically characterized by data that relate to specific testing methods. In general, these methods include the components required for evaluating simultaneously filling ability, passing ability, and resistance to segregation, since these properties are rather interrelated. In this investigation, 33 SCC mixtures made with various mixture proportioning parameters, including maximum size and type of aggregate, type and content of binder, and w/cm were evaluated. The mixtures were prepared using crushed aggregate and gravel of three different nominal sizes, w/cm of 0.33 and 0.38, and three binder compositions: Type MS cement, Type HE cement with 30% of slag replacement, and Type HE cement with 20% of Class F fly ash. Comparisons and correlations among various test results used in evaluating the workability responses obtained for these mixtures are established. This is done to highlight advantages and limitations of the various test methods that can be used to assess workability of SCC designated for prestressed applications. Appropriate combinations of test methods that can be used to assess workability of SCC at the precast plant are recommended, and ranges of acceptance of the various test methods are established.

Combinations of Various Self-Consolidating Concrete Test Methods and Workability Responses

2010 ◽  
Vol 150-151 ◽  
pp. 18-22
Author(s):  
Wu Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
Maximum Size ◽  
Test Methods ◽  
Test Results ◽  
Testing Methods ◽  
Mixture Proportioning ◽  
Self Consolidating Concrete ◽  
Filling Ability ◽  
Passing Ability

Key workability characteristics of SCC can be described in terms of filling ability, passing ability, and resistance to segregation. These properties are typically characterized by data that relate to specific testing methods. In general, these methods include the components required for evaluating simultaneously filling ability, passing ability, and resistance to segregation, since these properties are rather interrelated. In this investigation, 33 SCC mixtures made with various mixture proportioning parameters, including maximum size and type of aggregate, type and content of binder, and w/cm were evaluated. Comparisons and correlations among various test results used in evaluating the workability responses obtained for these mixtures are established. This is done to highlight advantages and limitations of the various test methods that can be used to assess workability of SCC designated for precast, prestressed applications. Ranges of acceptance of the various test methods are also established.

Comparative study of plastic property test methods for self-consolidating concrete

2012 ◽  
Vol 39 (8) ◽  
pp. 937-950 ◽  
Author(s):  
B. Shindman ◽  
D.K. Panesar
Keyword(s):  
Stability Index ◽  
Field Testing ◽  
Plastic Property ◽  
Test Methods ◽  
Plastic Properties ◽  
Self Consolidating Concrete ◽  
Filling Ability ◽  
Acceptance Limits ◽  
Passing Ability ◽  
Direct Measures

Currently, there are a variety of test methods to evaluate the plastic properties of self-consolidating concrete (SCC) specified in provincial, national, and international guidelines. There is, however, a dearth of knowledge on how the results of the various test methods compare with each other. Some of the tests are direct measures, others are indirect; some of the tests are qualitative and others are quantitative; and some tests have specified acceptance limits while others do not. The purpose of this study, initiated by the Ontario Ministry of Transportation (MTO), is to compare the plastic properties (filling ability, passing ability, and segregation resistance) of SCC and identify any correlations between them to determine the most appropriate test methods for evaluating the plastic properties of SCC. The filling ability (slump flow, L-box (t20 and t40), and V-funnel), passing ability (J-ring and L-box blocking ratio), and segregation resistance (visual stability index, column method, V-funnel (t5-t0)) tests are conducted on eight SCC mix designs. The results are compared to the acceptance criteria specified by the MTO for SCC. Based on the results, and their relationships, the plastic property tests most suitable for laboratory, prequalification, and field-testing are recommended.

Repeatability of Workability Test Methods of Self-Consolidating Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1981-1986
Author(s):  
Wu Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
Test Methods ◽  
Test Method ◽  
Upper And Lower Bounds ◽  
Test Results ◽  
Self Consolidating Concrete ◽  
Slump Flow ◽  
Single Operator ◽  
Crushed Aggregate ◽  
Relative Errors ◽  
Flow Consistency

In general, in the evaluation of a test method, the repeatability tests must be performed to establish upper and lower bounds for the precision of a test method. The repeatability is calculated as a standard deviation and relative error of test results. In order to evaluate the repeatability of the workability tests used in self-consolidating concrete (SCC) applications, an SCC mixture proportioned with 0.38 w/cm, Type MS cement, 480 kg/m3 of binder , and crushed aggregate with MSA of 12.5 mm was used. The dosage rate of the HRWRA of the SCC was adjusted to secure two initial slump flow consistency levels of 630 ± 10 mm and 700 ± 10 mm for the repeatability tests. For each consistency level, the concrete was batched five times (for a total of 10 mixtures). Each test was repeated five times by the same operator in order to establish the single-operator precision values. Furthermore, five different operators were used to perform each of the workability tests in order to assess the multi-operator error that could occur during testing. Based on the relative errors obtained in the repeatability tests, relatively low error values were obtained for the slump flow, J-Ring flow, and L-box blocking ratio tests. Relative errors for recommended SCC workability test methods were also summarized.

scholarly journals Study on Adaptability of Test Methods for Workability of Fresh Self-Compacting SFRC

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5312
Author(s):  
Xinxin Ding ◽  
Haibin Geng ◽  
Kang Shi ◽  
Li Song ◽  
Shangyu Li ◽  
...  
Keyword(s):  
Steel Fiber ◽  
Volume Fraction ◽  
Test Methods ◽  
Fiber Reinforced Concrete ◽  
Ring Test ◽  
Steel Fiber Reinforced Concrete ◽  
Slump Flow ◽  
Filling Ability ◽  
Flow Test ◽  
Passing Ability

To ensure the quality of concrete construction, the workability of fresh mix measured by rational test methods is critical to be controlled. With the presence of steel fibers, whether the test methods and evaluation indices of fresh self-compacting concrete (SCC) are adaptable for self-compacting steel fiber reinforced concrete (SFRC) needs to be systematically verified. In this paper, seven groups of self-compacting SFRC, referenced with one group SCC, were prepared by using the mix proportion design method based on the steel fiber-aggregates skeleton packing test. The main factors included the volume fraction and the length of hooked-end steel fiber. Tests for filling ability, passing ability, and stability of fresh self-compacting SFRC and SCC were carried out. Results indicate that the adaptability was well for the slump-flow test with indices of slump flow and flow time T500 to evaluate the filling ability, the J-ring flow test with an index of PA level to evaluate the passing ability, and the static segregation test with an index of static segregation resistance to evaluate the stability of fresh self-compacting SFRC. By the repeated tests and measurements, the slump cone should be vertically lifted off to a height of 300 mm within 3 s at a constant speed, the spacing of the rebar in the J-ring test should be adjusted to be two times the fiber length. If the table jumping test is used, the dynamic segregation percent should be increased to 35% to fit the result of the static segregation test. Good workability of the self-compacting SFRC prepared in this study is presented with the general evaluation of test results.

Correlations between Fresh Properties of Self-Consolidating Concrete Including Palm Oil Fuel Ash

2011 ◽  
Vol 250-253 ◽  
pp. 409-416 ◽  
Author(s):  
Md. Safiuddin ◽  
Md. Abdus Salam ◽  
Mohd Zamin Jumaat
Keyword(s):  
Palm Oil ◽  
Flow Time ◽  
Fresh Properties ◽  
Palm Oil Fuel Ash ◽  
Self Consolidating Concrete ◽  
Slump Flow ◽  
Filling Ability ◽  
Fuel Ash ◽  
Oil Fuel ◽  
Passing Ability

Palm oil fuel ash (POFA) has been used successfully as a supplementary cementing material in various types of concrete. In the present study, self-consolidating concrete (SCC) was produced by using POFA as a partial replacement of ordinary portland cement (OPC). In total, sixteen SCC mixes were prepared by varying water to binder (W/B) ratio, POFA content, and high-range water reducer (HRWR). POFA was used by replacing 0–30% of OPC by weight at the W/B ratios ranging from 0.25 to 0.40. The filling ability, passing ability and segregation resistance of various SCC mixes were investigated. The filling ability was determined with respect to slump flow, 50-cm slump flow time, inverted slump cone flow spread and time, and V-funnel flow time. The passing ability was examined with respect to J-ring flow. In addition, the segregation resistance was assessed with regard to sieve segregation index and column segregation factor. Based on the data obtained, the correlations for the fresh properties of SCC were sought. The experimental findings showed strong correlations between most of the fresh properties of SCC.

The Analysis on Materials Testing Network of Ecology Environment

2012 ◽  
Vol 427 ◽  
pp. 179-184
Author(s):  
Xin Chun Fang ◽  
Jian Zhong Sun ◽  
Rui Ping Kong ◽  
Lu Kui Shi
Keyword(s):  
Network Performance ◽  
Functional Materials ◽  
Test Methods ◽  
User Needs ◽  
Materials Testing ◽  
Network Technology ◽  
Test Results ◽  
Testing Methods ◽  
Network Testing ◽  
Balance Testing

As the network technology is widely used in the functional materials test of ecology environment, it becomes more and more important to balance testing network performance fast and accurately. However, there are so many network testing methods with a variety of user needs and different scopes. If we use these test methods indiscriminately, time and money is largely consumed, and the testing results often cannot meet user's requirements. Thus, while testing the network performance, in order to accelerate the speed of the material testing, and ensure the quality and the accuracy of test results, characteristics and user's requirements must be selected and improved.

Fresh Properties of Self-Compacting Concrete with Coarse Recycled Aggregate

2012 ◽  
Vol 602-604 ◽  
pp. 938-942 ◽  
Author(s):  
Wai Ching Tang
Keyword(s):  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Cement Content ◽  
Recycled Aggregate ◽  
Test Results ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Filling Ability ◽  
Passing Ability

In this paper, the fresh properties of self-compacting concrete (SCC) using recycled coarse aggregate (RCA) were evaluated. Five types of SCC mixtures were made, where the percentage of substitution of natural coarse aggregate by RCA was 0, 25, 50, 75 and 100%. The cement content, water to binder (W/B) ratio and Superplasticizer dosage were kept the same for all mixes. The effects of RCA on the key fresh properties such as filling ability, passing ability, and segregation resistance of SCC were investigated by conducting several fresh concrete tests included slump-flow, L-box, and sieve stability tests. The overall test results suggest that RCA can be used to produce SCC substituting up to 100% natural coarse aggregates without affecting the key fresh properties of concrete.

scholarly journals Self-Fibers Compacting Concrete Properties Reinforced with Propylene Fibers

2021 ◽  
Vol 28 (1) ◽  
pp. 64-72
Author(s):  
Jawad Ahmad ◽  
Fahid Aslam ◽  
Osama Zaid ◽  
Rayed Alyousef ◽  
Hisham Alabduljabbar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Construction Industry ◽  
Mechanical Performance ◽  
Negative Impact ◽  
Test Results ◽  
Split Tensile Strength ◽  
Filling Ability ◽  
Substitution Ratio ◽  
Passing Ability ◽  
Test Result

Abstract Self-Consolidating Concrete (SCC) has also brittle characteristics. This is unacceptable for any construction industry. The addition of fibers is one of the most common methods to enhance the tensile strength of concrete. Fiber controls the cracking phenomena and enhances the energy absorption capability of the concrete. On the other hand, the addition of fibers has a negative impact on the workability of fresh concrete. In this paper, a detailed study on the influence of Propylene fibers (PP) on the fresh properties of SCC was carried out. PFs were added into concrete mixes in a proportion of 1.0%, 2.0%, 3.0%, and 4.0% by weight of cement to offset its undesirable brittle nature and enhance its tensile strength. The fresh characteristics were evaluated based on its passing ability, flowability using, Slump flow, Slump T50 Spread time, L-Box and V-funnel tests as well as mechanical performance (compressive and split tensile strength) were also evaluated at 7,14 and 28 days curing. Test results indicate that the passing and filling ability decreased as the substitution ratio of PP increased. Besides, the test result indicates that strength was increased up to 2.0% addition of PP and then decrease gradually.

Research on the Milling Toughness of Black Silicon Carbide and the Repeatability of the Testing Results

2011 ◽  
Vol 487 ◽  
pp. 225-228 ◽  
Author(s):  
M. Liu ◽  
S.J. Jiang
Keyword(s):  
Silicon Carbide ◽  
Test Methods ◽  
National Standard ◽  
Black Silicon ◽  
Milling Machine ◽  
Test Results ◽  
Testing Methods ◽  
Factors Affecting ◽  
Steel Balls ◽  
Ball Mass

The toughness of abrasive grits means their resistance against breaking under the effect of cutting forces. The commonly used test methods include single crystal static compressing, rolling crushing, mould pressing, as well as milling. In the national standard “GB/T 23538-2009 Conventional Abrasive Testing Methods for Toughness (ball mill method)”, it is stipulated that milling machine is to be used for the abrasive grits F8-F150 to determine their toughness. This method by milling includes testing steps as follows: take a certain amount of abrasive grits , together with steel balls of certain size and certain mass, into the ball milling machine rotating at a certain speed .When the specified total rotations are completed, measure the ratio of the unbroken grits to the total amount of the milled samples. This ratio is defined as the milling toughness of the abrasive grits. In this paper, the milling toughness of different sized black silicon carbide is tested according to the requirement of “GB /T 23538-2009”, and the repeatability of the testing results characterized by test standard deviation is discussed. The test results from different operators using different ball mass are compared and analyzed, and the factors affecting the milling toughness test results are researched. Some suggestions to improve the repeatability of the test results are given.

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