scholarly journals HYDROTECHNICAL CONCRETE WITH LOCAL AGGREGATES AND THEM USING FOR MONOLITHIC STRUCTURES

2009 ◽  
Vol 1 (2) ◽  
pp. 102-110
Author(s):  
Vigantas Antanas Žiogas ◽  
Svajūnas Juočiūnas ◽  
Giedrius Žiogas
Keyword(s):  
Compressive Strength ◽  
Mass Loss ◽  
Frost Resistance ◽  
Strength Class ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Water Penetration ◽  
Total Mass Loss ◽  
Micro Cracks

The article discusses the technological peculiarities of construction monolithic hydrotechnical concrete structures, use of local aggregates for producing special concretes, methods of determining water impermeability of concretes as well as the evaluation of the methods mentioned above. The article presents the requirements for the granulometric composition of aggregate mixes for the production of flowing concrete mixes used for the construction of monolithic hydrotechnical structures. The possibilities and expediency of using local crushed gravel with increased amounts of weak particles for hydrotechnical structures are discussed. The mass loss of weak particles is slight compared with the whole mass of aggregates, and the total mass loss of crushed gravel it occurs due to micro-cracks present in particles. The frost resistance mark of crushed gravel and its suitability for hydrotechnical concretes should be determined by evaluating the amount of weak particles and their frost resistance. The article discusses concrete impermeability data received by means of two methods (according to LSTST 1974:2005 and LSTST EN 12390–8 requirements). Theoretical water penetration depths have been calculated. Determination of water impermeability according to LSTST 1974:2005 is recommended for C25/30 and lower compressive strength class concretes with W≤8. The LSTST EN 12390–8 water impermeability determina-tion method is recommended for C25/30 and higher compressive strength class concretes whose water impermea-bility mark is W≥8. For the construction of certain hydrotechnical structures water impermeable concretes whose water penetration depth should not exceed 20mm are recommended for use instead of the W6 and W8 concretes. Technological peculiarities and potential technological-organizational solutions for high walls of a water treatment plant have been discussed. The analysis of potential concreting methods of the reservoir’s high walls has been made as well as that of the key parameters of the continuous concreting process and their interaction. Dependences for the estimation of continuous concreting volumes and permissible concreted segment lengths have been proposed by evaluating the beginning of the intensive formation structure of concrete, number of layers in the height of the concreted wall and concreting intensity.

The influence of agitation on aggregates formed during treatment of water with a content of humic substances

2006 ◽  
Vol 6 (1) ◽  
pp. 211-218 ◽  
Author(s):  
L. Pivokonska ◽  
M. Pivokonsky
Keyword(s):  
Humic Substances ◽  
Velocity Gradient ◽  
Laboratory Tests ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Aluminium Chloride ◽  
Velocity Gradients ◽  
Perforated Baffle ◽  
Wide Size Distribution

This study aims to evaluate the influence of agitation conditions on the efficiency of the aggregation process when treating surface water containing humic substances. Laboratory tests were conducted by the jar tests using a variable speed paddle gang stirrer. Optimization of agitation intensity was determined by a Couette flocculator. Suspension was prepared using aluminium chloride as a destabilising reagent. Aggregation efficiency was evaluated by the determination of the degree of aggregation and by the test of aggregation. For all surface waters treated, the optimum treatability was demonstrated by applying higher velocity gradients (G=200–250 s−1). In addition to the laboratory tests, the plant measurements with water containing increased amounts of humic substances were taken to evaluate the aggregation efficiency. The results obtained by the aggregation efficiency measurements show that the intensity of agitation, with the assistance of perforated baffle-type flocculation chamber, attains a low level of velocity gradient (G=22–113 s−1), in contrast to the optimized velocity gradient level (G=200–250 s−1). The aggregates formed in the water treatment plant have an unsuitably wide size-distribution.

Reuse of water treatment plant sludge and dam sediment in brick-making

2001 ◽  
Vol 44 (10) ◽  
pp. 273-277 ◽  
Author(s):  
C. Huang ◽  
J.R. Pan ◽  
K.-D. Sun ◽  
C.-T. Liaw
Keyword(s):  
Compressive Strength ◽  
Water Treatment ◽  
Water Absorption ◽  
Satisfactory Result ◽  
Raw Materials ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
National Standard ◽  
Sintering Process ◽  
Water Treatment Plant Sludge

In this study, an attempt was made to use water treatment plant (WTP) sludge and dam sediment as raw materials for brick-making through the sintering process. The sinter of dam sediment fired at 1,050°C had a less than 15% ratio water absorption, and its compressive strength and bulk density met the Chinese National Standard (CNS) for first level brick. The WTP sludge sinter made under the same operating condition exhibited higher water absorption, larger shrinkage, but poorer compressive strength. When fired at 1,100°C, the shrinkage of the WTP sludge sinter was as high as 45%, although its compressive strength and water absorption of WTP sludge brick still met the standard for the first level brick. To reuse WTP sludge in an economical way, mixtures of various proportions of WTP sludge to dam sediment are used as raw materials. A satisfactory result was achieved when the ratio of the WTP sludge was less than 20% of the mixture. Results of tests indicated that the sinter of dam sediments which are fired at a temperature of 1000~1100°C has reached the requirement for tile brick.

scholarly journals The Effect of Adding Slag, Achieved from Wastewater Sludge Incineration in Fluidized-Bed Furnace, on the Quality of Concrete

2019 ◽  
Vol 1 (1) ◽  
pp. 244-250
Author(s):  
Alina Pietrzak
Keyword(s):  
Compressive Strength ◽  
Frost Resistance ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Wastewater Sludge ◽  
Hardened Concrete ◽  
Sludge Incineration ◽  
Concrete Mix ◽  
Compressive Strength Of Concrete

Abstract Due to a constant increase in generating the amount of sewage waste it is necessary to find an alternative method of its use or disposal. One of such methods can be utilization of sewage sludge in construction materials industry, particularly in concrete technology and other materials based on cement. It allows using waste materials as a passive additive (filler) or also as an active additive (replacement of part of bonding material). The article aims at presenting the analysis of the effect of adding slag, achieved from wastewater sludge incineration in sewage treatment plant, on properties and quality of concrete mix and hardened concrete. Using an experimental method, the researcher designed the composition of the control concrete mix, which was then modified by means of slag. For all concrete mixtures determined – air content with the use of pressure method and consistency measured by the use of concrete slump test. For all concrete series the following tests were conducted: compressive strength of concrete after 7, 28 and 56 days of maturing, frost resistance for 100 cycles of freezing and thawing, water absorption. The use of slag, ground once in the disintegrator, causes a decrease of in compressive strength of concrete samples in relation to the control concrete series as well as bigger decrease in compressive strength after frost resistance test.

scholarly journals Evaluation of the Performance Degradation of Hybrid Steel-Polypropylene Fiber Reinforced Concrete under Freezing-Thawing Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Daming Luo ◽  
Yan Wang ◽  
Ditao Niu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Mass Loss ◽  
Frost Resistance ◽  
Rough Set Theory ◽  
Mass Loss Rate ◽  
Splitting Tensile Strength ◽  
Fiber Reinforced Concrete ◽  
Hybrid Fibers ◽  
Flexural Toughness

The reasonable inclusion of hybrid fibers can leverage the advantages of each kind of fiber and enhance the frost resistance and flexural toughness of concrete. Previous studies on hybrid steel-polypropylene fiber reinforced concrete (HSPFRC) focused primarily on its mechanics instead of its frost resistance. In this work, the compressive strength, splitting tensile strength, mass loss rate, relative dynamic elastic modulus (RDEM), and flexural toughness of HSPFRC after freezing-thawing (F-T) are studied, and the relative importance of each factor affecting the frost resistance of HSPFRC is quantified by using fuzzy rough set theory. The results show that the inclusion of hybrid fibers has a noticeable effect on the frost resistance of HSPFRC after hundreds of F-T cycles and that the effect on the splitting tensile strength is greater than that on the compressive strength. After 500 F-T cycles, as the steel fiber (SF) content increases, the compressive strength and splitting tensile strength increase by factors of approximately 5 and 4, respectively, the flexural toughness is strengthened, and the mass loss rate is reduced by more than 90%. The addition of polypropylene fibers (PFs) has a relatively small effect on the strength of HSPFRC but reduces the mass loss of HSPFRC by almost 80%. However, the suitability of the RDEM for evaluating the frost resistance of HSPFRC remains uncertain. Quantified by fuzzy rough set theory, the weights of the factors affecting the frost resistance of HSPFRC are 0.50 (number of F-T cycles) > 0.35 (SF content) > 0.15 (PF content), verifying the experimental results.

scholarly journals VALIDATION OF THE METHODS OF Hg DETERMINATION ON WASTE WATER TREATMENT PLANT SAMPLES USING COLD VAPOUR-ATOMIC ABSORPTION SPECTROPHOTOMETER (CV-AAS)TECHNIQUES

2018 ◽  
Vol 16 (1) ◽  
pp. 10
Author(s):  
Rika Anggraini ◽  
Rita Hairani ◽  
Aman Sentosa Panggabean
Keyword(s):  
Atomic Absorption ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Atomic Absorption Spectrophotometer ◽  
Waste Water Treatment Plant ◽  
Cold Vapour ◽  
Repeatability And Reproducibility ◽  
Aas Method

The research about validation of the method of Hg determination on the sample from wastewater treatment plant (WWTP) PT. Badak NGL Bontang, Kalimantan Timur using cold vapour-atomic absorption spectrophotometer (CV-AAS) techniques has been conducted. To obtain a valid measurement result, determinations of the important several parameters that influence the method validation are used. The results of research showed that 20% SnCl2 solution could be used as a reducing agent. The analytic performance of measurement obtain is good, showed with the linearity (r) value ≥ 0.995, LOD was 0.2530 ppb, LOQ was 0.8432 ppb, MDL was 0.6427 ppb and repeatability and reproducibility are shown as % RSD < 2/3 CV Horwitz values. The accuracy of this method is very good with a percentage of recovery value of 114.88%. Based on the results of this research, CV-AAS method can be used in the determination of Hg in WWTP samples with the valid results.

PROPERTIES AND PERFORMANCE OF WATER TREATMENT SLUDGE (WTS)-CLAY BRICKS

2015 ◽  
Vol 77 (32) ◽  
Author(s):  
Mohd Asri Md Nor ◽  
Alia Syafiqah Abdul Hamed ◽  
Faisal Hj Ali ◽  
Ong Keat Khim
Keyword(s):  
Compressive Strength ◽  
Water Treatment ◽  
Water Absorption ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Water Treatment Sludge ◽  
X Ray ◽  
Clay Bricks ◽  
Firing Shrinkage ◽  
And Performance

Every year, large quantity of water treatment sludge (WTS) is produced from water treatment plant in Malaysia. Sanitary landfill disposal of sludge at authorized sites is the common practice in Malaysia. However, searching the suitable site for landfill is the major problem as the amount of sludge produced keeps on increasing. Reuse of the sludge could be an alternative to disposal. This study investigated the reusability of WTS as brick making material. The performance of clay-WTS bricks produced by mixing clay with different percentages of WTS with increments of 20% from 0% up to 100% was investigated. Each molded brick with optimum moisture content was pressed under constant pressure, oven-dried at 100˚C for 24 hours followed by heating at 600˚C for 2 hours and 1000˚C for 3 hours. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis were used to characterize clay, WTS and clay-WTS bricks.  The performance of the bricks were evaluated with firing shrinkage, loss on ignition (LOI), water absorption, bulk density, and compressive strength tests. Increasing the sludge content results in a decrease of brick firing shrinkage, and increase of water absorption and compressive strength. The results revealed that the brick with 100% by weight of sludge could generate the highest compressive strength of 17.123N/mm2. It can be concluded that the bricks with 20 to 100% of water treatment sludge comply with the Malaysian Standard MS7.6:1972, which can fulfill the general requirement for usage of clay bricks in wall construction.

Reagentless-Continuous Flow Method for Determination of Aqueous Ozone with Thin Film Semiconductor and Application to an Advanced Water Treatment Plant

1991 ◽  
Vol 23 (10-12) ◽  
pp. 1961-1968 ◽  
Author(s):  
T. Aoki ◽  
H. Oguro ◽  
K. Fujiyoshi ◽  
M. Yamamoto
Keyword(s):  
Thin Film ◽  
Water Treatment ◽  
Treatment Plant ◽  
Glass Tube ◽  
Water Treatment Plant ◽  
Treatment Processes ◽  
Relative Standard ◽  
Clean Air ◽  
Ultra Trace

A method without any reagent for the determination of ultra-trace aqueous ozone, utilizing a glass tube-separation process and a thin film semiconductor, is proposed. The glass tube was used as the separator to transfer ozone from water into a gas phase. Ozone was transferred into clean air flowing in the tube and then was continuously monitored at the thin film semiconductor. Signals were proportional to concentration of aqueous ozone more than 5 µ g/L. The relative standard deviation (n = 7) las 3.8 % at 7.6 µ g/L. The interference from hydrogen peroxide, mono-chloramine, and dichloramine, was completely eliminated. The present method was applied to an advanced water treatment pilot-plant incorporating two parallel treatment trains and was examined for its potential for monitoring aqueous ozone in treatment processes.

Sign in / Sign up

Export Citation Format

Share Document