Consolidation of cement-treated sewage sludge using vertical drains

2005 ◽  
Vol 42 (2) ◽  
pp. 528-540 ◽  
Author(s):  
J Chu ◽  
M H Goi ◽  
T T Lim
Keyword(s):  
Sewage Sludge ◽  
Land Reclamation ◽  
Model Tests ◽  
Waste Materials ◽  
Test Results ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Treated Sewage ◽  
The World

The disposal of sewage sludge and other waste materials has become a problem in many cities around the world. A study on the use of sewage sludge and other waste materials for land reclamation has been conducted. One of the methods studied is to dispose of the sludge after it has been mixed with binders or other waste materials and then to consolidate the mixture on site using surcharge and prefabricated vertical drains (PVDs). To study the consolidation behaviour of the sludge–binder mixtures around PVDs, model tests using a fully instrumented consolidation tank were conducted. Some of the test results are presented in this paper. The study shows that PVDs are effective in consolidating the sludge and binder mixtures, provided that the PVDs used can sustain large bending and resist corrosion by the chemicals in the sludge.Key words: consolidation, geoenvironmental, land reclamation, prefabricated vertical drains.

Vacuum preloading consolidation of reclaimed land: a case study

1998 ◽  
Vol 35 (5) ◽  
pp. 740-749 ◽  
Author(s):  
J Q Shang ◽  
M Tang ◽  
Z Miao
Keyword(s):  
Land Reclamation ◽  
Soil Improvement ◽  
Large Area ◽  
Vacuum Preloading ◽  
Reclaimed Land ◽  
Improvement Project ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Soft Clays

This case study presents the design, operation, and results of a soil improvement project using the vacuum preloading method on 480 000 m2 of reclaimed land in Xingang Port, Tianjing, China. The areas treated with vacuum ranged from 5000 to 30 000 m2. The effects of soil improvement are demonstrated through the average consolidation settlement of 2.0 m and increases in undrained shear strengths by a factor of two to four or more. The study shows that the vacuum method is an effective tool for the consolidation of very soft, highly compressive clayey soils over a large area. The technique is especially feasible in cases where there is a lack of surcharge loading fills, extremely low shear strength, soft ground adjacent to critical slopes, and access to a power supply.Key words: vacuum preloading consolidation, soil improvement, soft clays, land reclamation, prefabricated vertical drains.

scholarly journals Numerical Investigation to the Effect of Suction-Induced Seepage on the Settlement in the Underwater Vacuum Preloading with Prefabricated Vertical Drains

2021 ◽  
Vol 9 (8) ◽  
pp. 797
Author(s):  
Shu Lin ◽  
Dengfeng Fu ◽  
Zefeng Zhou ◽  
Yue Yan ◽  
Shuwang Yan
Keyword(s):  
Practical Implication ◽  
Soil Surface ◽  
Small Strain ◽  
Seepage Flow ◽  
Excess Pore Pressure ◽  
Combined Effects ◽  
Vacuum Preloading ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
The Difference

Vacuum preloading combined with prefabricated vertical drains (PVDs) has the potential to improve the soft sediments under water, however, its development is partly limited by the unclear understanding of the mechanism. This paper aims to extend the comprehension of the influential mechanism of overlapping water in the scenario of underwater vacuum preloading with PVDs. The systematic investigations were conducted by small strain finite element drained analyses, with the separated analysis schemes considering suction-induced consolidation, seepage and their combination. The development of settlement in the improved soil region and the evolution of seepage flow from the overlapping water through the non-improved soil region into improved zone are examined in terms of the build-up of excess pore pressure. Based on the results of numerical analyses, a theoretical approach was set out. It was capable to estimate the time-dependent non-uniform settlement along the improved soil surface in response to the combined effects of suction-induced consolidation and seepage. The difference of underwater and onshore vacuum preloading with PVDs is discussed with some practical implication and suggestion provided.

scholarly journals Applying Mixture of Municipal Incinerator Bottom Ash and Sewage Sludge Ash for Ceramic Tile Manufacturing

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3863
Author(s):  
Deng-Fong Lin ◽  
Wei-Jhu Wang ◽  
Chia-Wen Chen ◽  
Kuo-Liang Lin
Keyword(s):  
Wear Resistance ◽  
Sewage Sludge ◽  
Water Absorption ◽  
Ceramic Tile ◽  
Bending Strength ◽  
Bottom Ash ◽  
Waste Materials ◽  
Sewage Sludge Ash ◽  
Kiln Temperature ◽  
Sludge Ash

Municipal incinerator bottom ash (MIBA) and sewage sludge ash (SSA) are secondary wastes produced from municipal incinerators. Landfills, disposal at sea, and agricultural use have been the major outlets for these secondary wastes. As global emphasis on sustainability arises, many have called for an increasing reuse of waste materials as valuable resources. In this study, MIBA and SSA were mixed with clay for ceramic tile manufacturing in this study. Raw materials firstly went through TCLP (Toxicity Characteristic Leaching Procedure) to ensure their feasibility for reuse. From scanning electron microscopy (SEM), clay’s smooth surface was contrasted with the porous surface of MIBA and SSA, which led to a higher water requirement for the mixing. Specimens with five MIBA mix percentages of 0%, 5%, 10%, 15%, and 20% (wt) and three SSA mix percentages of 0%, 10%, and 20% (wt) were made to compare how the two waste materials affected the quality of the final product and to what extent. Shrinkage tests showed that MIBA and SSA contributed oppositely to tile shrinkage, as more MIBA reduced tile shrinkage, while more SSA encouraged tile shrinkage. However, as the kiln temperature reached 1150 °C, the SiO2-rich SSA adversely reduced the shrinkage due to the glass phase that formed to expand the tile instead. Both MIBA and SSA increased water tile absorption and reduced its bending strength and wear resistance. Increasing the kiln temperature could effectively improve the water absorption, bending strength, and wear resistance of high MIBA and SSA mixes, as SEM showed a more compact structure at higher temperatures. However, when the temperature reached 1100 °C, more pores appeared and seemingly exhausted the benefit brought by the higher temperature. Complex interactions between kiln temperature and MIBA/SSA mix percentage bring unpredictable performance of tile shrinkage, bending strength, and water absorption, which makes it very challenging to create a sample meeting all the specification requirements. We conclude that a mix with up to 20% of SSA and 5% of MIBA could result in quality tiles meeting the requirements for interior or exterior flooring applications when the kiln temperature is carefully controlled.

Concrete Beams Reinforced with GFRP Plates

2017 ◽  
Vol 747 ◽  
pp. 220-225
Author(s):  
Alberto Pedro Busnelli ◽  
Ruben Edgardo López ◽  
Jorge Carlos Adue
Keyword(s):  
Glass Fiber ◽  
Carbon Fibers ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
The World ◽  
Critical Resistance

This is the presentation of the research carried out by the Faculty of Engineering at Universidad Nacional de Rosario on the use of pultruded Glass Fiber Reinforced Polymer (GFRP) plates to increase the flexural strength of reinforced concrete beams.Pultruded plates are the type of elements made of composite materials which are most widely used for this kind of strengthening. Although around the world the material used for these plates is carbon fibers, its high cost prevents its widespread use in our country.One of the aims of our research program is, precisely, to verify whether it is possible to substitute such plates for significantly cheaper glass fiber elements manufactured in Argentina. The test results have proved that this alternative is feasible.What's more, the greater thickness of the glass fiber plates allows the use of additional anchor bolts. These bolts provide the system with post-critical resistance and ductility-characteristics which are absolutely necessary, for example, in structures in seismic areas.

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