scholarly journals Experimental Investigation on Pouring Aggregate to Plug Horizontal Tunnel with Flow Water

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1763 ◽  
Author(s):  
Gailing Zhang ◽  
Shuang Hui ◽  
Weixin Li ◽  
Wanghua Sui
Keyword(s):  
Experimental Investigation ◽  
Critical Velocity ◽  
Water Flow ◽  
Gravitational Force ◽  
Coarse Aggregate ◽  
Solid Particles ◽  
Fine Aggregate ◽  
Mass Ratio ◽  
Range Analysis ◽  
Tunnel Model

This paper presents an experimental investigation on the main factors that influence the effects of pouring aggregate to plug a tunnel that has been inundated by groundwater to reduce the flow velocity. Moreover, a criterion for plugging the tunnel under infiltrating water to resist flow is proposed. A range analysis and analysis of variance both show that the influencing factors on the efficiency of plugging in descending order is the aggregate particle size, followed by initial velocity of the water flow, and then the water–solid mass ratio. The sedimentation process of the aggregate is likened to the deposition of solid particles into slurry in which the particles settle under gravitational force, thus accumulating at the bottom of the tunnel model due to the forces of the water flow and gravity. The critical velocity of the water that will transport the aggregate without settling can be used as a criterion to determine whether there has been a successful plug of the resistance to flow in the tunnel. The experimental results show that the critical velocity of fine aggregate is less than that of coarse aggregate, and the section with smaller sized aggregate or fine aggregate that resists water flow is flatter. In addition, the required minimum space between two pouring boreholes for a successful resistance to flow is discussed.

scholarly journals Development of Ultra High Strength Concrete Using Silica Fume and its Mechanical & Durability Properties - Experimental Investigation

2021 ◽  
Author(s):  
Sathyakumar N ◽  
Arun M ◽  
Arunachalam N
Keyword(s):  
Experimental Investigation ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Chloride Penetration ◽  
Fine Aggregate ◽  
Strength Concrete ◽  
Super Plasticizer

Abstract This experimental investigation is aimed to develop an ultra-high strength concrete with minimum of 100 MPa as compressive strength.In order to obtain this, twenty different concrete mixes have been tried, using cement, river sand, coarse aggregate, water, silica fume and super plasticizer. During the preparation of trial mixes of concrete, the water / binder ratio of 0.2, silica fume of 10% to the weight of cement, super plasticizer of 10 litres per cubic metre of concrete and coarse aggregate of 1000 kg/m3 were kept as constant. The amount of cement content (as 600-, 650-, 700-, 750- and 800 kg/m3) and the fine aggregate content (as 500-, 600-, 700- and 800 kg/m3) was varied. Totally 300 specimens were cast and tested in this investigation.The100 x 100 x 100 mm size of cubes, 150 x 300 mm size of cylinders, 100 x 100 x 500 mm size of prisms, 100 x 200 mm size of cylinders, 60 x 100 mm size of cylinders were used to test compressive, split tensile, flexural strength, chloride penetration and water penetration tests respectively at the age of 7-, 14- and 28 days. Based on the test results, a suitable mix proportion to produce an ultra-high strength concrete has been identified. Subsequently, from this investigation, the maximum cube compressive strength of 130 MPa, split tensile strength of 6.94 MPa, flexural strength of 21.39 MPa, chloride penetration 36 Coulombs which is lesser than 100 and sorptivity coefficient valueof 0.582 has been achieved.

Experimental Investigation of a Two-Phase (Air-Water) Flow in a Pipe with Street Canyon Cavities

2014 ◽  
Vol 8 (6) ◽  
pp. 1149
Author(s):  
Dimitra A. Zoga ◽  
Dimitrios S. Georgakis-Gavrilis ◽  
Dionissios P. Margaris
Keyword(s):  
Experimental Investigation ◽  
Water Flow ◽  
Street Canyon ◽  
Two Phase

Studies on effect of steel fiber and coarse aggregate on fracture properties of self compacting concrete using wedge splitting test

2019 ◽  
Vol 11 (6) ◽  
pp. 751-767
Author(s):  
Raja Rajeshwari B. ◽  
Sivakumar M.V.N.
Keyword(s):  
Fracture Energy ◽  
Coarse Aggregate ◽  
Peak Load ◽  
Mouth Opening ◽  
Test Method ◽  
Crack Mouth Opening Displacement ◽  
Fine Aggregate ◽  
Content Type ◽  
Fracture Properties ◽  
Splitting Test

Purpose Fracture properties depend on the type of material, method of testing and type of specimen. The purpose of this paper is to evaluate fracture properties by adopting a stable test method, i.e., wedge split test. Design/methodology/approach Coarse aggregate of three different sizes (20 mm, 16 mm and 12.5 mm), three ratios of coarse aggregate, fine aggregate (CA:FA) (50:50, 45:55, 40:60), presence of steel fibers, and specimens without and with guide notch were chosen as parameters of the study. Findings Load-crack mouth opening displacement curves indicate that for both fibrous and non-fibrous mixes, higher volume of aggregate and higher size of coarse aggregate have high fracture energy. Originality/value For all volumes of coarse aggregate, it was noticed that specimens with 12.5 mm aggregate size achieved highest peak load and abrupt drop post-peak. The decrease in coarseness of internal structure of concrete (λ) resulted in the increase of fracture energy.

Sign in / Sign up

Export Citation Format

Share Document