Corrosion Control Characteristics of Low Density Cellular Concrete Grout for Final Steel Liners for Tunnels

2009 ◽  
Author(s):  
Graham E. C. Bell
Keyword(s):  
Low Density ◽  
Corrosion Control ◽  
Final Steel ◽  
Cellular Concrete

Soft Soil Remediation with Permeable Low-Density Cellular Concrete

IFCEE 2021 ◽  
2021 ◽  
Author(s):  
Nico Sutmoller ◽  
Milton Gomez ◽  
John T. Kevern
Keyword(s):  
Soil Remediation ◽  
Soft Soil ◽  
Low Density ◽  
Cellular Concrete

Investigation on Improvement of Flexural Behavior of Low-Density Cellular Concrete through Fiber Reinforcement for Non-Structural Applications

2019 ◽  
Vol 2673 (10) ◽  
pp. 641-651
Author(s):  
Arman Abdigaliyev ◽  
Jiong Hu
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Construction Material ◽  
Flexural Behavior ◽  
Unit Weight ◽  
Slight Reduction ◽  
Low Density ◽  
Hybrid Fibers ◽  
Structural Applications ◽  
Cellular Concrete

During the last decades, cellular lightweight concrete (CLC), or foamed concrete, has been experiencing greater interest in geotechnical, structural, and non-structural applications. The low density and high flowability makes it a favorable construction material in relation to handling, placing, and construction costs. However, the applications of low-density cellular concrete (LDCC), the category of CLC with a unit weight less than 50 pounds per cubic foot (801 kg/m3) and generally without fine aggregates, are limited mostly to backfill applications in geotechnical engineering. The main reason lies in the brittleness of the material and low to zero resistance to flexural loads. Fiber-reinforced LDCC may be a reasonable solution to improve mechanical properties and expand the application range of the material. This study investigated the effects of adding polypropylene and hybrid fibers on physical and mechanical properties of LDCC and the feasibility of expanding LDCC utilization to non-structural applications. Results showed that although there is a slight reduction of flowability and compressive strength, the flexural behavior of LDCC can be significantly improved with the incorporation of fibers. The flexural strength and flexural toughness of LDCC was found to increase from 26.8 pounds per square inch (psi) (0.18 MPa) to 217.5 psi (1.48 MPa), and from 5.67 lb-in. (0.64 kN-mm) to 292 lb-in. (33.0 kN-mm) respectively at a 1.0% addition rate of a fibrillated polypropylene fiber selected in this study, which makes it a feasible material for non-structural applications.

scholarly journals INVESTIGATION INTO LOW DENSITY POROUS CONCRETE PENETRABILITY BY AIR/MAŽO TANKIO AKYTOJO BETONO ORO LAIDUMO TYRIMAI

1996 ◽  
Vol 2 (7) ◽  
pp. 41-45 ◽  
Author(s):  
Antanas Laukaitis ◽  
Laima J. Kunskaitė
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Low Density ◽  
Product Density ◽  
Porous Concrete ◽  
Acoustical Properties ◽  
Concrete Production ◽  
Cement Binder ◽  
Mixture Samples ◽  
Cellular Concrete

Low-density (250–350 kg/m3) porous concrete has good thermal insulation and acoustical properties. However, the determination of these properties requires a lot of time and is rather costly. Changes in these properties can be determined, if the porous concrete air penetrability, which can be simply found, is known. This paper deals with porous concrete made using Portland cement binder and a binder mixture (lime + Portland cement), as well as with foam concrete air penetrability coefficient value dependency on its density and water/dry solids ratio V/K. The raw materials composition is given in Table 1. Fig. 1 represents the air penetrability determination apparatus scheme. Air penetrability increases with a decrease of density in porous concrete sample. For example, when V/K=0.6 and product density decreases from 490 to 310 kg/m3, the air penetrability coefficient increases from 2.5·10−7to 13.1·10−7 m3/m·S·Pa. Porous concrete air penetrability increases with an increase in V/K (Fig. 2.). The air penetrability coefficient increases from 6·6·10−7 to 12.8·10−7 m3/m·S·Pa when the product density is 350 kg/m3 and V/K changes from 0.5 to 0.7. Changes in V/K have a greater influence on low density porous concrete air penetrability. That is why, when slowly hydrating Portland cement is used for porous concrete production, foaming formation mixture temperature is not high, it binds and is cured very slowly. For higher density product pore structures such a slow curing process does not have any effects, because small, spherical pores prevail. When the water content is increased in the formation mixture, a change in product porous structure is observed, because larger deformed coupled pores are formed and therefore the air penetrability increases. An air penetrability dependency on product density and V/K regression equation (3) is given. Air penetrability coefficients of porous concrete made using a mixed binder (lime + Portland cement) are given in Table 2. It has been established, that a 20% Portland cement equivalent amount of lime in the binder mixture according to equation 1 and when the V/K ratio increased from 0.52 to 0.65, the some density product air penetrability coefficient of equal density products increased by 3 times, while the lime content in the binder increased from 20 to 80% from formation mixture samples with V/K ratio =0.52. Air penetrability of porous concrete made using a mixed binding material also depends on concrete density and formation mixture V/K ratio (Fig. 3.). Cellular concrete air penetrability coefficient values are given in Fig. 4. Cellular concrete differs from porous concrete, because its air penetrability coefficient values decrease with an increase in V/K ratio. This is the reason why cellular concrete air penetrability coefficients are lower than those of porous concrete. Cellular concrete air penetrability coefficient dependency on product density and V/K ratio is expressed by equation 4.

The AVR (HTGR) Decommissioning Project With New Strategy

2007 ◽  
Author(s):  
Hakan Sterner ◽  
Dieter Rittscher
Keyword(s):  
Fission Products ◽  
Vessel Diameter ◽  
Reactor Vessel ◽  
Primary System ◽  
Low Density ◽  
Successful Operation ◽  
Activation Products ◽  
Reactor Building ◽  
New Strategy ◽  
Cellular Concrete

The 15-MWel prototype pilot reactor AVR is a pebble bed HTGR. It was designed in the late 50s and was connected to the grid end of 1967. After 21y of successful operation the reactor was shut down end of 1988. In 1994 the first decommissioning license was granted and work with defueling, dismantling and preparation of a Safe Enclosure started. The primary system is contaminated with the fission products Sr90 and Cs137 and the activation products are Co60, C14 and H3. Due to the large amounts of Sr and Cs bound to graphite dust, the dismantling of systems connected to the pressure vessel is very tedious. In 2003 the AVR company was restructured and the strategy of the decommissioning was changed from safe enclosure to green field, i.e. the complete direct dismantling of all facilities and clean up of the site. The highlight during the dismantling is the removal of the reactor vessel (diameter ca. 7.6m and length ca. 26m) in one piece. Before handling the reactor vessel it will be filled with low density cellular concrete. Subsequently the reactor building will be cut open and the reactor vessel (total weight ca. 2100Mg) lifted out and transported to an interim store.

scholarly journals Permeable low-density cellular concrete (PLDCC) as a replacement for aggregate layers in permeable parking lots

2021 ◽  
pp. 100060
Author(s):  
Sundeep Inti ◽  
Thomas Evans ◽  
Michael Flores ◽  
Jayraj Singh Solanki ◽  
Chandramouli V. Chandramouli
Keyword(s):  
Low Density ◽  
Parking Lots ◽  
Cellular Concrete

Soft Soil Settlement Remediation and Roadway Elevation Increase with Permeable Low-Density Cellular Concrete (PLDCC)

2021 ◽  
Author(s):  
Justin Eskew ◽  
Kevin Hill ◽  
Larry Madrid ◽  
Nico Sutmoller ◽  
Lawrence “Connor” Updike
Keyword(s):  
Soft Soil ◽  
Low Density ◽  
Soil Settlement ◽  
Cellular Concrete

Low Density Cellular Concrete Made of Reftinskaya SDPP Fly Ash

2017 ◽  
Vol 265 ◽  
pp. 124-128 ◽  
Author(s):  
A.A. Vishnevskiy ◽  
F.L. Kapustin
Keyword(s):  
Fly Ash ◽  
Single Layer ◽  
Drying Shrinkage ◽  
Strength Properties ◽  
Low Density ◽  
Concrete Technology ◽  
Concrete Production ◽  
Aerated Concrete ◽  
Increased Strength ◽  
Cellular Concrete

There is experience of the production and use of low density autoclaved aerated concrete. It is shown that fly-ash from Reftinskaya State District Power Plant efficiently substitutes the quartz sand aerated concrete technology. Its use opens up additional opportunities for AAC with the density of 300-400 kg/m3. In order to optimize the structure and properties it has been suggested to introduce the gypsum aerated concrete additive into the autoclave in the amount of 3-5% by weight of the dry components. The introduction of gypsum ensures the creation of a uniform homogeneous structure, resulting in the increased strength properties and reduced drying shrinkage. The resulting aerated concrete has thermal conductivity of 0.075-0.100 W/m·K, it allows using and creating single-layer fencing structures without additional insulation. The low-density gas-ash concrete production allows extending the scope of cellular concrete application and increasing its competitive advantages over other walls and insulating materials.

scholarly journals Soft Soil Remediation with Permeable Low-Density Cellular Concrete (PLDCC)

2019 ◽  
Vol 271 ◽  
pp. 02002
Author(s):  
Nico Sutmoller ◽  
Milton Gomez ◽  
John Kevern
Keyword(s):  
Case Studies ◽  
Soil Remediation ◽  
Kansas City ◽  
Soft Soil ◽  
Low Density ◽  
University Of Missouri ◽  
Chester County ◽  
Void Structure ◽  
The University ◽  
Cellular Concrete

This paper addresses the feasibility of using permeable low-density cellular concrete (PLDCC) in soft soil remediation applications. In discussing this feasibility, the paper will review and evaluate data from recent studies conducted at the University of Missouri Kansas City related to the physical properties of PLDCC, including permeability, infiltration, and void structure. This paper will cover the most typical applications for the utilization of PLDCC and take a brief look at the constructability and cost considerations. Three specific case studies are examined, including a wall abutment project in Bellingham, WA, a structural foundation project in New Orleans, LA, and a sinkhole remediation project in Chester County, PA. All three of these case studies utilized 25 to 35 pcf (pounds per cubic foot) (400 kg/m3 to 560 kg/m3) PLDCC for soft soil remediation.

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