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

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.

2012 ◽  
Vol 6 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Wu-Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing

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.


2010 ◽  
Vol 150-151 ◽  
pp. 18-22
Author(s):  
Wu Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing

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.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5312
Author(s):  
Xinxin Ding ◽  
Haibin Geng ◽  
Kang Shi ◽  
Li Song ◽  
Shangyu Li ◽  
...  

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.


2011 ◽  
Vol 250-253 ◽  
pp. 409-416 ◽  
Author(s):  
Md. Safiuddin ◽  
Md. Abdus Salam ◽  
Mohd Zamin Jumaat

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.


1969 ◽  
Vol 9 (04) ◽  
pp. 403-411 ◽  
Author(s):  
B.K. Sinha ◽  
Harvey T. Kennedy

Abstract Recommendations are made for obtaining consistent and reproducible test data on drilling fluids having identical composition. Previously, such a procedure has been difficult to accomplish even when the fluids were mixed in similar equipment. A survey of work in this area indicates that previous methods have been unsatisfactory because previous methods have been unsatisfactory because (1) the muds are extremely sensitive to the duration and violence of agitation during a normal mixing routine, and (2) gelling of the muds occurs before the properties can reach constant values. This gelling is caused by water evaporation resulting from the increase in temperature associated with the agitation. The work shows that these problems largely can be overcome by (1) agitating the constituents of the drilling fluid more vigorously, (2) maintaining a fairly constant temperature, and(3) Protecting the fluid from evaporation. When these steps are followed, the fluid properties approach asymptotic values that do not change by prolonged or accelerated agitation or by aging for a month. The time required to reach asymptotic values or a stabilized state is from 2 to 6 hours and is a function of the mud composition. Introduction Preparation of drilling fluids in the laboratory to determine their suitability to meet specific drilling requirements or to serve as a base fluid to evaluate the effectiveness of thinners, dispersants or other additives normally begins with combining measured quantities of the constituents and stirring them for a short time in a low-speed mixer. This is done to obtain a uniform mixture and to hydrate clays. Then the fluid is further agitated in a higher-speed device (Hamilton Beach mixer or Waring blender) to disperse more thoroughly and clay particles The biggest obstacle in the laboratory investigation of drilling fluids has been the lack of a method of producing a mixture by which reproducible results of the measured properties could be obtained. Numerous investigators have encountered this difficulty. Prior to 1929, density was the only property of mud that customarily was measured. The use of Wyoming bentonite on a large scale after 1929 was mainly responsible for the development of more elaborate testing procedures and for the application of the principles of colloid chemistry to the drilling fluids. Ambrose and Loomis in 1931 were among the first to recognize the plastic flow characteristics of drilling fluids, although Bingham in 1916 had observed The same phenomenon with dilute clay suspensions. Marsh introduced the Marsh funnel for field testing in 1931. By this time, non-Newtonian characteristics of drilling fluids were established. The Stormer and MacMichael viscometers were used to study the rheological properties of the fluids. In the 1930's and early 1940's, the work conducted by several investigators contributed toward a better understanding of drilling fluids. In the mid 1930's, fluid-loss and the associated mud-cake-forming properties of drilling fluids were recognized as important to the behavior of these fluids. The other properties of drilling fluids, including gel strength, pH, and sand content soon were recognized. In 1937, API published its first recommended procedure for test methods. Since that time, these procedures have been revised periodically. The latest edition, RP-13B, was published in 1961 However, in spite of the recognized need for a method of mixing that provides drilling fluids with stabilized properties, no such method previously has been described. SPEJ P. 403


Author(s):  
M. A. Kukharenko ◽  
V. A. Mokhoreva

The article presents various methods for determining the strength and plastic properties of the wire to assess the quality characteristics of the products produced in the steel shops of JSC «BMW – the Management Company of the Holding «BMC».The methods of determining the propensity of a thin wire to laminations by reversing the twisting («Swedish» twist) and unilateral twisting, fixing the length change of the sample with a prefix with the dial indicator are considered. The article describes the procedure and results of research to determine the effect of the ratio of the conditional yield strength to the time resistance of the rupture on the plastic properties of the wire, the type of tensile diagram of the wire fragility.


2011 ◽  
Vol 306-307 ◽  
pp. 946-950 ◽  
Author(s):  
Bao Guo Ma ◽  
Hui Xian Wang ◽  
Jia Xiao ◽  
Li Xia Li ◽  
Zhi Bin Cheng

Viscosity modifying admixtures (VMA), known as an important component, are water-soluble polymers that can increase the viscosity and cohesion of self-compacting concrete( SCC). This article presents the effect of four different types of VMA on the workability of SCC , which including flowability, filling ability, passing ability and segregation resistance ability of the fresh concrete. The results show that the low viscosity of VMA satisfies the workability requirement of fresh properties of SCC.


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