scholarly journals Evaluating the applicability of rheometry in steel fiber reinforced self-compacting concretes

2016 ◽  
Vol 9 (6) ◽  
pp. 969-988 ◽  
Author(s):  
R. S. Alferes Filho ◽  
◽  
F. K. Motezuki ◽  
R. C. O. Romano ◽  
R. G. Pileggi ◽  
...  
Keyword(s):  
Construction Industry ◽  
Steel Fiber ◽  
Rheological Parameters ◽  
Experimental Program ◽  
Test Results ◽  
Slump Flow ◽  
Flow Test ◽  
Conventional Tests ◽  
Fresh State ◽  
Passing Ability

ABSTRACT The use of self-compacting concrete in civil construction industry presents various advantages, since the material shows adequate workability during fresh state. When fiber reinforcement is used, there are changes in its behavior that require attention. This study aimed to evaluate the applicability of rheological tests and the correlation between its results and those obtained with regular tests used to control SCCs. In that sense, different mixtures of SCC with different steel fiber contents were produced in order to be analyzed in the experimental program described. Rotational rheology tests and slump flow and L-box tests were performed. The results showed that slump flow test did not present good correlations with rheological parameters. On the other hand, this test was able to point out the risk of segregation of the mixtures with higher fiber contents. A good correlation was obtained between the L-box test results and rheological parameters. The L-box was also able to show loss in the passing ability of SCC related to the rise of plastic viscosity and yield stress. These tests also presented a good correlation with the rheological parameters when lower fiber contents were used. Although the rheometry test was unable to evaluate these problems, this kind of test gave more objective and reliable data on variations in rheological parameters related to the increase of fiber content, and proved to be a more reliable test to this kind of application, especially when applied together with the conventional tests.

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.

Specifications and testing of self-consolidating mortar designated for annular space grouting

2011 ◽  
Vol 38 (4) ◽  
pp. 422-432 ◽  
Author(s):  
Soo-Duck Hwang ◽  
Kamal H. Khayat ◽  
Richard Morin
Keyword(s):  
High Stability ◽  
Fine Sand ◽  
Underground Water ◽  
Experimental Program ◽  
Testing Protocol ◽  
Slump Flow ◽  
Nominal Size ◽  
Repair Mortars ◽  
Passing Ability ◽  
Good Filling

An experimental program was undertaken to evaluate the performance of self-consolidating mortar designed for filling small annular spaces for the rehabilitation of underground water line or sewage pipelines. The study also intended to establish a testing protocol to validate the workability of repair grout. All the investigated mixtures had good filling and passing ability with adequate retention of workability over 3 h. The repair mortars exhibited high stability with bleeding lower than 0.3% compared to 3% bleeding in the case of the reference neat cement grout. The reference grout had a lower plastic viscosity and higher slump flow values than the sanded repair grouts. A V-funnel with 30 mm × 30 mm overture and a flow cone with 12.7 mm overture are recommended for mortar made with concrete sand with a 5 mm nominal size and micro mortar with fine sand with a nominal size up to 3 mm, respectively.

scholarly journals Performance of Flowable Concrete in Underground Structures

2021 ◽  
Author(s):  
Sandip Sonule ◽  
H.Jayarama
Keyword(s):  
Test Results ◽  
Underground Structures ◽  
Long Distance ◽  
Experimental Procedure ◽  
Slump Flow ◽  
Flow Test ◽  
Natm Tunnel ◽  
Metro Project ◽  
Successful Production

Abstract Flowable concrete gives special combinations of uniformity, performance and consistency requirements that cannot be possible by traditional normal slump concrete. It is more superior concrete than the traditional concrete with high workability without segregation, bleeding, and is also suitable for use on structures with long distance pumping i.e., more than 120-meter length, for example, in NATM tunnels and cross-passages, and the concrete structure of the station box. Flowable concrete can flow itself without vibration or little bit vibration like surface tamping outer surface of the formwork for achieving a smooth surface finish after de-shuttering. The proportion of the mix is to be used in concrete, it must ensure a balance between deformability and stability. The behavior of concrete can be influenced by the properties of the selected item in the concrete, and the aspect ratio of the mixture. There is a need for the development of a methodology for the design of the flowable concrete mix. The paper presents an experimental procedure for the mix design of flowable concrete for grade M40 and implementation of the same mix at the cast in situ Base slab, Roof slab Rcc walls for underground metro stations, NATM tunnel & cross passages in Mumbai Metro Project, package -UGC-07. The test results for acceptance characteristics of M40 grade flowable concrete such as Slump flow test, compressive strength at the ages of 7, 28, and 56 days determined, and results are included here. Successful production of temperature control flowable concrete from batching plant, transportation, placement procedures, and proper planning of handling and execution of flowable concrete at the site are presented in this article.

Utilization of Iron Filings as Partial Replacements for Sand in Self-Compacting Concrete

2021 ◽  
Vol 47 (3) ◽  
pp. 906-916
Author(s):  
Simon O. Olawale ◽  
Mutiu A. Kareem ◽  
Habeeb T. Muritala ◽  
Abiola U. Adebanjo ◽  
Olusegun O. Alabi ◽  
...  
Keyword(s):  
Steel Production ◽  
Strength Properties ◽  
Self Compacting Concrete ◽  
River Sand ◽  
Slump Flow ◽  
Filling Ability ◽  
Fine Aggregates ◽  
Concrete Production ◽  
Fresh State ◽  
Passing Ability

The use of industrial by-products in concrete production is part of concerted efforts on the reduction of environmental hazards attributed to the mining of conventional aggregates. Consideration of iron filings (IF), a by-product from steel production process, is an environmentally friendly way of its disposal which is expected to yield economic concrete production. Six self-compacting concrete (SCC) mixes were made by partially substituting river sand with IF at 5%, 10%, 15%, and 20% and the mix without IF (0% IF) served as the control. The water-binder (w/b) ratio of 0.45 was adopted for all mixes. The fresh state properties of SCC evaluated include: filling ability determined using slump flow and T500 mm slump flow tests, passing ability determined using L-box test and segregation resistance determined using V-funnel tests. The strength properties of SCC considered were compressive and tensile strengths. All the SCC mixes met the fresh properties requirements for filling capacity, passing ability, and segregation resistance. The 28-day compressive and tensile strengths of SCC increased by 3.46% and 8.08%, respectively, with IF replacement up to 15% compared to the control SCC. However, there was reduction in compressive and tensile strengths of SCC with IF replacement beyond 15%. The strength properties of SCC is considerably enhanced with the addition of up to 15% IF. Hence, the optimum content of 15% IF is considered suitable as a replacement for river sand in SCC. Keywords: Self-compacting concrete; iron filings; fine aggregates; filling ability; passing ability

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.

scholarly journals Effect of Recycled Concrete Waste Aggregate on the Fresh State Properties of Self Compacting Concrete

2019 ◽  
Vol 8 (6) ◽  
pp. 1070-1073
Keyword(s):  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Mineral Admixture ◽  
Self Compacting Concrete ◽  
State Tests ◽  
Slump Flow ◽  
Filling Ability ◽  
Fresh State ◽  
Passing Ability

In this investigation an attempt is made to replace coarse aggregate partially or fully by recycled concrete waste aggregates and the fresh state properties of modified SCC (Self Compacting Concrete) was elaborated by conducting slump flow, V-funnel, L-Box and J-ring tests. The properties such as filling ability, passing ability, segregation, bleeding and stability of the modified SCC were determined by using the fresh state tests. The results of this experiment revealed that it is possible to modify SCC by partially or fully replacing the coarse aggregate by RCWA. The optimum mix also determined by varying RCWA and mineral admixture content in SCC.

scholarly journals Study of cement pastes rheological behavior using dynamic shear rheometer

2014 ◽  
Vol 7 (6) ◽  
pp. 922-939
Author(s):  
J. E. S. L. Teixeira ◽  
V. Y. Sato ◽  
L. G. Azolin ◽  
F. A. Tristão ◽  
G. L. Vieira ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Scientific Community ◽  
Flow Characteristics ◽  
Bingham Fluid ◽  
Material Behavior ◽  
Rheological Parameters ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Flow Test ◽  
Fresh State

Concrete, in its fresh state, has flow characteristics that are crucial to its proper launch and densification. These characteristics are usually measured through empirical testing as the slump test, but this test does not quantify completely the material behavior. Since this material is characterized as a Bingham fluid, it is essential the study of its rheological behavior to verify its properties even in fresh state. The use of classical rheology has been employed by the scientific community to obtain rheological parameters determinants to characterize this material, such as yield stress, plastic viscosity and evolution of shear stress to shear rate. Thus, this present study aims to determine the rheological behavior of different cement pastes produced with cement CP III 40 RS, varying between them the hydration periods (20 and 60 min), the water-cement ratio (0.40, 0.45 and 0.50) and the use or not of additive. Samples were assayed by flow test to determine the rheological parameters showing the effect of the variables mentioned above in these parameters.

Rheology of Mortar and its Influences on Performance of Self-Consolidating Concrete

2008 ◽  
Vol 400-402 ◽  
pp. 421-426 ◽  
Author(s):  
I.Y.T. Ng ◽  
P.L. Ng ◽  
A.K.H. Kwan
Keyword(s):  
High Performance ◽  
Cementitious Materials ◽  
Experimental Program ◽  
Test Results ◽  
Self Consolidating Concrete ◽  
Slump Flow ◽  
Starting Point ◽  
Pulverized Fuel ◽  
Good Starting Point ◽  
Pulverized Fuel Ash

A two-part experimental program is presented in this paper. In the first part, four self-consolidating mortar mixes were designed with different compositions of cementitious materials including cement, pulverized fuel ash and condensed silica fume. For each SCM mix composition, the superplasticizer dosage was varied and a total of 30 batches of mortar were produced. For every batch of mortar, the rheology was determined by a rheometer and the workability was measured by the mini slump flow test and the mini V-funnel test. From the test results, the saturation SP dosage of each SCM mix was determined. In the second part, four self-consolidating concrete mixes were produced, each comprising a SCM mix with saturation SP dosage and a fixed coarse aggregate content. The workability, filling and passing abilities and segregation stability were measured by the slump flow, U-box and sieve segregation tests, respectively. It was found that the performance of all the SCC mixes was satisfactory. The test results suggested that using a SCM mix with saturation SP dosage as the mortar phase can produce SCC with high performance and therefore is a good starting point to optimize the performance of SCC mixes.

Production of Self-Compacting Concrete Using Rock Breaking Waste Residues

2013 ◽  
Vol 785-786 ◽  
pp. 157-162 ◽  
Author(s):  
Fabio Nascimento ◽  
Luisa Andréia Gachet-Barbosa ◽  
Rosa Cristina Cecche Lintz ◽  
Maria Rachel Russo Seydell
Keyword(s):  
Mechanical Performance ◽  
Rock Breaking ◽  
Strength Test ◽  
State Technical ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Flow Test ◽  
Fresh State ◽  
Hard State ◽  
State Water

Waste residues derived from the breaking process of rocks have been many times inadequately discarded on the environment generating an environmental passive. The residues could be used in the production of self-compacting concrete (CAA) providing more sustainable constructions. To study different CAA mixtures the following tests have been performed in the fresh state: Water Absorption, L - Box, V - Funnel and Slump Flow Test. For the evaluation of mechanical performance, the concrete Compression Strength Test, Flexural Strength Test and Tensile Strength by Diametric Compression Test have been performed in the hard state. Technical and environmental viability in the addition of this type of residue for the studied percentages have been verified.

scholarly journals Self-compacting Concrete with Alccofine and Glass Fiber

2019 ◽  
Vol 9 (1S3) ◽  
pp. 188-191
Keyword(s):  
Glass Fiber ◽  
Ultrafine Particles ◽  
External Work ◽  
Self Consolidating Concrete ◽  
Pozzolanic Material ◽  
Slump Flow ◽  
Flow Test ◽  
Strength Tests ◽  
Fresh State ◽  
Hardened State

Self consolidating concrete (S.C.C.) is a type of concrete which need not be provided any kind of external work for compaction and gets consolidated by own weight and thereby providing a lot of economic and technical benefits. It flows under own weight to completely fill forms and pass without segregation, through closely spaced reinforcement. Alccofine is a pozzolanic material and the ultrafine particles of Alccofine provide better workability, strength as well as the economy. Properties of M40 S.C.C. control mix was compared with S.C.C. mixes incorporating 1% of glass fiber and replacing different percentages (0%, to 15% by weight) of cement with Alccofine was studied. Optimum replacement of cement was assessed by studying properties in the fresh state and in the hardened state, and then comparing results with properties of control mix. Fresh state properties of S.C.C. were assessed by L box test, slump-flow test and V funnel test. Compressive strength, flexural strength, and splitting tensile strength tests were done to assess hardened state properties. Properties of S.C.C. in Fresh and hardened state were seen to be enhanced by addition of Alccofine and Glass fiber.

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