A STATIC APPROACH FOR DETERMINING RHEOLOGICAL PROPERTIES OF SELF-COMPACTING CONCRETE (POWDER AND VMA TYPE) BY USING DIRECT SHEAR BOX TEST METHOD

2020 ◽  
Vol 10 (2) ◽  
pp. 27
Author(s):  
N. AJAY ◽  
S. GIRISH ◽  
M. JOSHI ASHWIN ◽  
◽  
◽  
...  
Keyword(s):  
Rheological Properties ◽  
Test Method ◽  
Direct Shear ◽  
Self Compacting Concrete ◽  
Static Approach ◽  
Shear Box ◽  
Direct Shear Box Test

Simulating a direct shear box test by DEM

2006 ◽  
Vol 43 (2) ◽  
pp. 155-168 ◽  
Author(s):  
S H Liu
Keyword(s):  
Contact Angle ◽  
Internal Friction ◽  
Granular Material ◽  
Distinct Element ◽  
Contact Forces ◽  
Interparticle Contact ◽  
Direct Shear ◽  
Angle Of Internal Friction ◽  
Shear Box ◽  
Direct Shear Box Test

Distinct element simulation was performed for direct shear box (DSB) tests on a dense and a loose two-dimensional (2D) sample of 3259 cylinders. Special attention was devoted to the effect that the frictional force between the inside surface of the upper shear box and the sample had on the measured shear strength in the DSB test. Some ways of minimizing this interface frictional force were introduced in the paper. Given that the deformation approximates simple shear within the deforming zone across the sample centre (referred to as the shear zone), a method was proposed to evaluate the overall strains in the DSB test. The numerically simulated data were used to interpret, on a microscopic scale, the angle of internal friction and a 2D stress–dilatancy equation for the mobilized plane in granular material. It was found that the angle of internal friction in granular material is not directly related to the interparticle friction angle (ϕµ). Instead, it relates to the average interparticle contact angle ([Formula: see text]) on the mobilized plane and the ratio k/f0, representing the degree of the probability distribution of the interparticle contact forces that is biased toward the positive zone of the contact angle θ (along the shear direction), where k is the slope of the linear distribution of the average interparticle contact forces against the interparticle contact angle; and f0 is the average interparticle contact force.Key words: angle of internal friction, direct shear box test, distinct element method, friction, granular material, stress–dilatancy.

scholarly journals Determining the Rheological Properties of Fresh Concrete using Concrete Shear Box

2019 ◽  
Vol 9 (1) ◽  
pp. 351-360
Keyword(s):  
Rheological Properties ◽  
Research Study ◽  
Fresh Concrete ◽  
Relative Yield ◽  
Test Method ◽  
Portland Cement Concrete ◽  
Test Device ◽  
Model Study ◽  
Repeatability And Reproducibility ◽  
Shear Box

A test method which is accurate, viable and is based on the fundamental scientific description and at the same time the results are independent of the test device can go a long way in better understanding of the workability of fresh concrete. The principal objective of this research study is to assess the feasibility of concrete shear box to measure the rheological properties of fresh Portland cement concrete using Bingham model. Study assesses the repeatability and reproducibility of the results. The repeatability values of relative yield stress and relative plastic viscosity are 97.63% and 91.49% and reproducibility values are 91.68% and 95.51% respectively and the results reinforce the effectiveness of using concrete shear box.

Finite element analysis of the direct shear box test

Géotechnique ◽  
1987 ◽  
Vol 37 (1) ◽  
pp. 11-23 ◽  
Author(s):  
D. M. Potts ◽  
G. T. Dounias ◽  
P. R. Vaughan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Direct Shear ◽  
Element Analysis ◽  
Shear Box ◽  
Direct Shear Box Test

scholarly journals Evaluation of Micro-Mechanism and High- and Low-Temperature Rheological Properties of Disintegrated High Volume Crumb Rubber Asphalt (DHVRA)

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1145
Author(s):  
Wei Li ◽  
Sen Han ◽  
Xiaokang Fu ◽  
Ke Huang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Particle Diameter ◽  
Gel Permeation Chromatography ◽  
High Volume ◽  
Crumb Rubber ◽  
Test Method ◽  
Polar Component ◽  
Temperature Performance

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm−1 caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.

scholarly journals Time-Dependent Response of a Recycled C&D Material-Geotextile Interface under Direct Shear Mode

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3070
Author(s):  
Fernanda Bessa Ferreira ◽  
Paulo M. Pereira ◽  
Castorina Silva Vieira ◽  
Maria de Lurdes Lopes
Keyword(s):  
Shear Stress ◽  
Stress Relaxation ◽  
Shear Displacement ◽  
Time Dependent ◽  
Shear Behaviour ◽  
Displacement Rate ◽  
Shear Mode ◽  
Direct Shear ◽  
Constant Displacement ◽  
Shear Box

Geosynthetic-reinforced soil structures have been used extensively in recent decades due to their significant advantages over more conventional earth retaining structures, including the cost-effectiveness, reduced construction time, and possibility of using locally-available lower quality soils and/or waste materials, such as recycled construction and demolition (C&D) wastes. The time-dependent shear behaviour at the interfaces between the geosynthetic and the backfill is an important factor affecting the overall long-term performance of such structures, and thereby should be properly understood. In this study, an innovative multistage direct shear test procedure is introduced to characterise the time-dependent response of the interface between a high-strength geotextile and a recycled C&D material. After a prescribed shear displacement is reached, the shear box is kept stationary for a specific period of time, after which the test proceeds again, at a constant displacement rate, until the peak and large-displacement shear strengths are mobilised. The shear stress-shear displacement curves from the proposed multistage tests exhibited a progressive decrease in shear stress with time (stress relaxation) during the period in which the shear box was restrained from any movement, which was more pronounced under lower normal stress values. Regardless of the prior interface shear displacement and duration of the stress relaxation stage, the peak and residual shear strength parameters of the C&D material-geotextile interface remained similar to those obtained from the conventional (benchmark) tests carried out under constant displacement rate.

Test Methods for Rheological Properties of Self-Compacting Concrete Pastes

2011 ◽  
Vol 338 ◽  
pp. 396-400
Author(s):  
Bao Guo Ma ◽  
Hui Xian Wang ◽  
Jian Huang ◽  
Liu Qing Song
Keyword(s):  
Rheological Properties ◽  
Cement Paste ◽  
Test Methods ◽  
General Study ◽  
Self Compacting Concrete ◽  
Cement Pastes ◽  
Different Types ◽  
Over Time

This paper provides a general study on cement paste flow which derived from self- compacting concretes. Rheometer, Marsh cone and mini-slump cone were used to evaluate fluidity of cement pastes containing superplasticizers of different types and dosages and loss of fluidity over time. There is a superplasticizer saturation dosage beyond which no significant fluidity increase can be found. This paper evaluated the effect of these three methods using rheometer as control and the optimum superplasticizer type for the preparation of self-compacting concrete was suggested.

scholarly journals STUDY ON RHEOLOGICAL PROPERTIES OF FRESH CONCRETE WITH MODEL MATERIALS BASED ON SHEAR BOX TEST

1998 ◽  
Vol 63 (511) ◽  
pp. 17-24 ◽  
Author(s):  
Ken-ichi TERADA ◽  
Yasuo TANIGAWA ◽  
Hiroshi MORI ◽  
Yoshiyuki KUROKAWA ◽  
Naoki MISHIMA ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Fresh Concrete ◽  
Shear Box
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