scholarly journals Reuse of Waste Material “Waste Sludge Water” from a Concrete Plant in Cement Composites: A Case Study

2019 ◽  
Vol 9 (21) ◽  
pp. 4519
Author(s):  
Klus ◽  
Václavík ◽  
Dvorský ◽  
Svoboda ◽  
Botula
Keyword(s):  
Cement Mortar ◽  
Fresh Concrete ◽  
Hardened Cement ◽  
Cement Composites ◽  
Complete Replacement ◽  
Economic Problems ◽  
Waste Sludge ◽  
Recycled Waste ◽  
Mixing Water

This paper presents the results of research dealing with the use of recycled waste sludge water from a concrete plant (CP) as partial or complete replacement of mixing water in cement mixtures. The need to recycle waste sludge water generated as a by-product (waste sludge water) during the production of fresh concrete in the concrete plant results from the environmental and economic problems associated with the operation of the concrete plant. Mixing water was replaced with recycled waste sludge water in the amount of 25%, 50%, 75%, and 100%. In order to determine the effect of partial or complete replacement of mixing water with waste sludge water from the concrete plant in the production of cement composites, laboratory tests of waste sludge water were carried out to determine whether the waste sludge water complies with the requirements for mixing water defined in CSN EN 1008. The tests also determined the properties of fresh cement mortar and hardened cement composites. These were tests of the beginning and end of cement mortar setting, and the strength characteristics (flexural strength, compressive strength). The results of these tests show that it is possible to replace the mixing water by waste sludge water from the concrete plant in the amount of up to 25% without significantly affecting the tested properties, in comparison with the formula containing pure mixing water.

scholarly journals The effect of CO2 on cement composites produced with an admixture of waste sludge water from a concrete plant

2019 ◽  
Vol 14 (1) ◽  
pp. 39-46
Author(s):  
Lukas Klus ◽  
Jakub Svoboda ◽  
Vojtech Václavik ◽  
Tomas Dvorský ◽  
Jiri Botula
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Laboratory Tests ◽  
Strength Characteristics ◽  
Cement Composites ◽  
Mineralogical Analysis ◽  
Complete Replacement ◽  
Waste Sludge ◽  
Mixing Water

Abstract This article presents the results of a research dealing with the effect of CO2 on cement composites prepared on the basis of waste sludge water from the concrete plant. The designed formulas R1 and R3 use waste sludge water from the concrete plant as a partial or complete replacement of mixing water in the production of cement composites. The mixing water was replaced by waste sludge water in the amounts of 25%, 50%, 75% and 100%. Laboratory tests that are defined in ČSN EN 1008 standard were performed in order to determine the effect of partial or complete replacement of mixing water. The test specimens were further subjected to the effect of CO2 in the Lamart laboratory chamber, where the effect of CO2 was simulated for the period 50 years. Subsequently, the cement composites were tested for their strength characteristics (tensile flexural strength, compressive strength) and subjected to a mineralogical analysis. The results show that the effect of CO2 will reduce the strength characteristics of the composite compared to the comparative samples.

scholarly journals Frost resistance of cement composites prepared on the basis of waste water from a concrete plant

2018 ◽  
Vol 13 (1) ◽  
pp. 123-132
Author(s):  
Lukas Klus ◽  
Vojtech Vaclavik ◽  
Jakub Svoboda ◽  
Jindrich Sancer
Keyword(s):  
Waste Water ◽  
Portland Cement ◽  
Experimental Research ◽  
Frost Resistance ◽  
Resistance Coefficient ◽  
Resistance Test ◽  
Cement Composites ◽  
Recycled Water ◽  
Recycled Waste ◽  
Mixing Water

Abstract This article presents the results of a research dealing with the use of waste water from concrete industry as a possible substitution of mixing water during the production of cement composites. This experimental research involved the preparation of two recipes of cement composites, named R1 and R3. Mixing water in these recipes was replaced with waste water from a concrete plant in the amount of 25, 50, 75 and 100%. Samples of recycled waste water, which were tested for the content of sulphates, chlorides and alkali according to ČSN EN 1008, were taken in order to determine the properties of waste water from a concrete plant. The prepared test specimens were tested for frost resistance after 100 freezing cycles according to ČSN 73 1322. The results of the frost resistance test showed that the required value of the frost resistance coefficient of 0.75 according to ČSN 73 1322 was achieved only in case of recipe R1 based on Portland cement CEM I 52.5R and 75 and 100% substitution of the mixing water with recycled water from a concrete plant.

The Utilization of a Combination of Recycled Rubber from Waste Tires and Waste Waters from a Concrete Plant in the Production of Cement Composites

2020 ◽  
Vol 838 ◽  
pp. 59-66
Author(s):  
Jakub Svoboda ◽  
Vojtěch Václavík ◽  
Tomáš Dvorský ◽  
Lukáš Klus ◽  
Jiří Botula
Keyword(s):  
Cement Composite ◽  
Partial Replacement ◽  
Cement Composites ◽  
Rubber Material ◽  
Waste Tires ◽  
Waste Sludge ◽  
Mortar Strength ◽  
Recycled Rubber ◽  
Mixing Water ◽  
Physical And Mechanical Characteristics

This article presents the results of a study dealing with the use of a combination of recycled rubber from waste tires as a 100% replacement of aggregate and waste sludge water from a concrete plant as a partial replacement of mixing water in the production of cement composites. The aggregate was replaced with recycled rubber material in two ratios. The first ratio was 50/50 and the other one was a 40/60 ratio of fraction 0/1 mm and fraction 1/3 mm. The mixing water was replaced with waste sludge water from a concrete plant in the amounts of 25% and 50%. The designed cement composite formulas were subjected to the test of their physical and mechanical characteristics in order to determine the properties when using a combination of recycled rubber and waste sludge water from a concrete plant. The tested properties include: consistency of the grain curve, mixing water properties, consistency of cement mortar, strength characteristics (tensile flexural strength and compressive strength). The study presents the results that are fundamentally different from the comparative samples and their use in the building industry but, at the same time, they also open up new possibilities of their use as building material.

scholarly journals Effect of Hydrogen Nanobubbles on the Mechanical Strength and Watertightness of Cement Mixtures

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1823
Author(s):  
Won-Kyung Kim ◽  
Young-Ho Kim ◽  
Gigwon Hong ◽  
Jong-Min Kim ◽  
Jung-Geun Han ◽  
...  
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Cement Mortar ◽  
Stable State ◽  
Pozzolanic Reaction ◽  
Hydration Reaction ◽  
High Concentration ◽  
Mercury Intrusion ◽  
Electron Microscope Analysis ◽  
Mixing Water ◽  
Cement Mixtures

This study analyzed the effects of applying highly concentrated hydrogen nanobubble water (HNBW) on the workability, durability, watertightness, and microstructure of cement mixtures. The number of hydrogen nanobubbles was concentrated twofold to a more stable state using osmosis. The compressive strength of the cement mortar for each curing day was improved by about 3.7–15.79%, compared to the specimen that used general water, when two concentrations of HNBW were used as the mixing water. The results of mercury intrusion porosimetry and a scanning electron microscope analysis of the cement paste showed that the pore volume of the specimen decreased by about 4.38–10.26%, thereby improving the watertightness when high-concentration HNBW was used. The improvement in strength and watertightness is a result of the reduction of the microbubbles’ particle size, and the increase in the zeta potential and surface tension, which activated the hydration reaction of the cement and accelerated the pozzolanic reaction.

scholarly journals Preparation and Mechanical Properties of Graphene Oxide: Cement Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Fakhim Babak ◽  
Hassani Abolfazl ◽  
Rashidi Alimorad ◽  
Ghodousi Parviz
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Cement Mortar ◽  
Cement Matrix ◽  
Cement Composites ◽  
Xrd Diffraction ◽  
Calcium Silicate Hydrates ◽  
The Matrix ◽  
Scanning Electron

We investigate the performance of graphene oxide (GO) in improving mechanical properties of cement composites. A polycarboxylate superplasticizer was used to improve the dispersion of GO flakes in the cement. The mechanical strength of graphene-cement nanocomposites containing 0.1–2 wt% GO and 0.5 wt% superplasticizer was measured and compared with that of cement prepared without GO. We found that the tensile strength of the cement mortar increased with GO content, reaching 1.5%, a 48% increase in tensile strength. Ultra high-resolution field emission scanning electron microscopy (FE-SEM) used to observe the fracture surface of samples containing 1.5 wt% GO indicated that the nano-GO flakes were well dispersed in the matrix, and no aggregates were observed. FE-SEM observation also revealed good bonding between the GO surfaces and the surrounding cement matrix. In addition, XRD diffraction data showed growth of the calcium silicate hydrates (C-S-H) gels in GO cement mortar compared with the normal cement mortar.

scholarly journals The use of recycled waste products in a sustainable house design - a case study

2018 ◽  
Vol 196 ◽  
pp. 04051
Author(s):  
Agnes Iringová
Keyword(s):  
Physical Parameters ◽  
Renewable Materials ◽  
Recycled Materials ◽  
Waste Products ◽  
Current State ◽  
Waste Production ◽  
House Design ◽  
Family House ◽  
Recycled Waste

The current state of waste production and management in Slovakia. Legislative regulations. Analysis of applying recycled waste products in the construction of sustainable buildings as a substitution of non-renewable materials. The comparison of the physical parameters of recycled materials with non-renewable materials in terms of thermal and fire protection. The construction solution of lightweight building envelopes with a timber supporting system using the thermal insulation and facing made of recycled materials. The model solution of a wood-based family house using recycled waste materials. The comparison of the environmental burden of a standard lightweight sandwich peripheral wall with a recycled waste wall.

scholarly journals Microfinance as Employment Generation Tool (Case Study of Pakistan 2001-02 to 2010-11)

2014 ◽  
Vol 13 (5) ◽  
pp. 4506-4509
Author(s):  
Muhammad Saleh Memon ◽  
Mohammad Asif Channa ◽  
Izhar Ali Manganhar
Keyword(s):  
Rural Community ◽  
Quantitative Research ◽  
Poverty Reduction ◽  
Living Standard ◽  
Sustainable Solutions ◽  
Economic Problems ◽  
Secondary Sources ◽  
Employment Generation ◽  
Economic Survey

The objective of this study is to know the contributions of Micro finance towards employment development through generating employment opportunities to the alit class of urban and rural community. For this purpose quantitative research techniques were used to collect the data. The data was collected through secondary sources from economic survey from 2011-12 and labor force survey 2010-2011 and from annual plans of Pakistan from 2001-02 to   2012-13. Mainly 8 to 10 micro finance banks and micro finance institutes and some NGOs are taken into study.  The results express the positive contributions of micro finance to the employment that leads to poverty reduction and improved living standard. In contrast micro finance through supporting the employment generates sustainable solutions of other economic problems like poverty, good education, better health etc. 

Grip of Mature and Fresh Concrete with Heat Treatment in Winter Conditions

2020 ◽  
Vol 992 ◽  
pp. 111-117
Author(s):  
V.V. Molodin ◽  
S.E. Sarafyan ◽  
D.S. Kasyanova
Keyword(s):  
Sea Water ◽  
Fresh Concrete ◽  
Protective Layer ◽  
Cement Clinker ◽  
Hardened Concrete ◽  
Climatic Zones ◽  
Winter Conditions ◽  
Sulfide Corrosion ◽  
Port Infrastructure ◽  
Mixing Water

Port infrastructure facilities, located in cold climatic zones in contact with sea water, are destroyed due to carbonation of concrete and sulfide corrosion. The restoration of the reinforcement protective layer by standard methods does not provide high-quality grip of the concrete structures that has undergone destruction and the repair concrete. The study of the “old” and “new” concrete grip using forced heating of the “new” one shows that mixing water with cement clinker components dissolved in it penetrates through the pores and capillaries deep into the “old” concrete to a depth of 60–70 mm under the temperature factor influence. After hardened concrete got its standard strength, it exceeds concrete grip, hardened under normal conditions by 30%.

scholarly journals Mechanical Properties and Microscopic Mechanism of Coral Sand-Cement Mortar

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Luoxin Wang ◽  
Junshuai Mei ◽  
Jing Wu ◽  
Xingyang He ◽  
Hainan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cement Mortar ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Hardened Cement ◽  
Hydration Reaction ◽  
Microscopic Mechanism ◽  
X Ray ◽  
Volume Stability ◽  
Coral Sand

The workability and mechanical performance of coral sand-cement mortar (coral mortar, for short) and the modification effects of mineral admixtures on the coral mortar were studied in this paper. The results showed that the strength of coral mortar was lower than that of standard mortar, but the strength of coral mortar was improved by compositing with the mineral admixture, which can be attributed to the improvement of the microstructure and interface transition area. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to explore the microscopic mechanism involved in the mechanical properties, volume stability, and hydration of mortar. The analyses revealed that the internal curing effect of coral sand improved the mechanical properties of mortar and its ability to resist shrinkage. The uneven surface of coral sand formed a meshing state of close combination with the hardened cement mortar, which helped to improve the volume stability of mortar. The Ca2+ and Mg2+ ions from coral sand participated in the hydration reaction of cement, which contributed to generating more hydration products. Moreover, the microaggregate filling and pozzolanic effects of fly ash and slag improved the mechanical properties of coral mortar and resistance to chloride ion diffusion.

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