scholarly journals Study on Properties of Waste Concrete Powder by Thermal Treatment and Application in Mortar

2020 ◽  
Vol 10 (3) ◽  
pp. 998 ◽  
Author(s):  
Yuwu Sui ◽  
Chuping Ou ◽  
Shu Liu ◽  
Jinshuai Zhang ◽  
Qingbo Tian
Keyword(s):  
Particle Size ◽  
Thermal Treatment ◽  
Treatment Process ◽  
Activity Index ◽  
Recycled Aggregate ◽  
Thermal Treatments ◽  
High Quality ◽  
Active Elements ◽  
Waste Concrete ◽  
Mechanical Strengths

Waste concrete must be crushed, screened, and ground in order to produce high-quality recycled aggregate. In this treatment process, 15–30% waste concrete powder (<0.125 mm) can be generated. Hydration activity and the reuse of waste concrete powders (WCPs) were studied in this work, and the results illustrated that the particle size changed after a series of thermal treatments at temperatures from 400 ℃ to 800 ℃. The particle size of waste concrete powder decreased by 700 ℃ thermal treatment, and by 600 ℃ thermal treatment, it increased. More active elements appeared in WCP heated by 800 ℃. Nevertheless, the activity index (AI) of WCP, measured by the ratio of mechanical strengths between mortar with a 30% replacement of the cement with WCP and normal mortar without WCP, indicated that the WCP by 700 ℃ thermal treatment had an optimal AI value, which meant WCP treated at 700 ℃ could be used in mortar or concrete as an admixture.

The High Quality Technical Research of Road Concrete Recycled Coarse Aggregate

2011 ◽  
Vol 346 ◽  
pp. 47-51 ◽  
Author(s):  
M. Mandula ◽  
Xiao Yu Hu ◽  
Feng Jin Chen ◽  
Wen Long Zhang
Keyword(s):  
Coarse Aggregate ◽  
Chemical Characteristic ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Cement Slurry ◽  
High Quality ◽  
Ordinary Concrete ◽  
Recycled Coarse Aggregate ◽  
Waste Concrete ◽  
Physical And Chemical

This paper studies the recycling of solid waste concrete of the foundational content. Through the experimental research on the use of recycled aggregate and recycled concrete powder, I propose recycled coarse aggregate, recycled powder of various physical and chemical characteristic and the powder mixed with cement slurry mixed with recycled coarse aggregate on the surface of the mechanical properties after treatment. The results show that the coarse aggregate crushing value after surface treatment, strength characteristics of concrete can meet the requirements of ordinary concrete.

Advanced Process for Recovery of High Quality Recycled Aggregate from Waste Concrete

2006 ◽  
Vol 9 (2) ◽  
pp. 45-48
Author(s):  
Ji-Whan Ahn ◽  
Kwang-Suk You ◽  
Gi-Chun Han ◽  
Nam-Il Um ◽  
Hee-Chan Cho
Keyword(s):  
Recycled Aggregate ◽  
High Quality ◽  
Waste Concrete

scholarly journals A multilevel investigation supported by multivariate analysis for tomato product formulation

2021 ◽  
Author(s):  
Fatma Boukid ◽  
Elena Curti ◽  
Agoura Diantom ◽  
Eleonora Carini ◽  
Elena Vittadini
Keyword(s):  
Thermal Treatment ◽  
Color Change ◽  
Water Molecules ◽  
Thermal Treatments ◽  
Industrial Processing ◽  
H Nmr ◽  
Mobile Populations ◽  
Product Formulation ◽  
Tomato Product ◽  
The Impact

AbstractIndustrial processing of tomato includes its cutting and mincing, thermal treatments, and the addition of ingredients, which might induce changes in physicochemical properties of the final products. In this frame, the impact of texturing/thickening [xanthan gum (X) or potato fiber (F)] on the macroscopic, mesoscopic and molecular properties of tomato double concentrate (TDC) was investigated to determine if F can efficiently substitute X, in association with small solutes (sugar and salt) and thermal treatment (cold and hot). At a macroscopic level, multivariate statistics (MANOVA) underlined that color change (ΔE) was increased by X and F addition contrary to heating and the addition of salt and sugar. MANOVA revealed that texture was greatly enhanced through the use of F over X. 1H NMR molecular mobility changes were more controlled by texturing agents (F and X) than thermal treatment and small solutes. Particularly F increased the more rigid population indicating stronger interaction with water molecules resulting in shear-thinning flow. However, adding X contributed into the increase of the dynamic and mobile populations. Therefore, F can be a valid “clean label” substitute of X in modulating tomato products properties.

A model to predict the kinetics of mass loss in wood during thermo-vacuum modification

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ottaviano Allegretti ◽  
Ignazia Cuccui ◽  
Nasko Terziev ◽  
Laerte Sorini
Keyword(s):  
Mass Loss ◽  
Treatment Process ◽  
Linear Trend ◽  
Thermal Modification ◽  
Thermal Treatments ◽  
Temperature Profiles ◽  
Relative Area ◽  
Heat Power ◽  
Kinetics Of

AbstractMass loss (ML) of wood caused by thermal degradation is one of the most important features of the thermal treatments and referred to as an indicator of intensity and quality of the process. The ML is proportional to the quantity of the effective heat power exchanged during the treatment process, represented by the area of the temperature profile versus time during the process. In this paper a model for the ML prediction based on the relative area was discussed. The model proposed an analytical solution to take into account the non-linear trend of ML when plotted versus temperature and time as observed in isothermal experiments. The model was validated comparing calculated and measured final ML of samples treated during thermal modification tests with different temperature profiles. The results showed that the relative area calculated in a transformed time-temperature space improves the correlation with the measured ML.

Effects of maximum particle size of coarse aggregates and steel fiber contents on the mechanical properties and impact resistance of recycled aggregate concrete

2021 ◽  
pp. 136943322110179
Author(s):  
DongTao Xia ◽  
ShaoJun Xie ◽  
Min Fu ◽  
Feng Zhu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Steel Fiber ◽  
Impact Resistance ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Coarse Aggregates ◽  
Maximum Particle Size ◽  
Maximum Particle

Fiber reinforced recycled aggregate concrete has become a new type of green concrete material. The maximum particle size of coarse aggregates and steel fiber contents affect the mechanical properties and impact resistance of recycled aggregate concrete. However, such studies are rare in literature. The present paper shortens the gap through experimental study. A total of 144 specimens of 12 kinds of concrete mixtures were tested, which adopted different steel fiber volume admixtures (0%, 0.8%, 1.0%, 1.2%) and recycled coarse aggregates in different maximum particle sizes (9.5, 19, 31.5 mm) replacing 30% natural coarse aggregate. The compressive strength, splitting tensile strength, and impact resistance of the 12 concrete mixtures were tested. The results showed that the compressive strength, splitting tensile strength, and impact resistance of recycled aggregate concrete increased first and then decreased with the increase of the maximum particle size. The recycled aggregate concrete with the maximum particle size of 19 mm had the highest mechanical properties and impact resistance. Besides, with the increase of steel fiber content, the compressive strength, splitting tensile strength, and impact resistance of recycled aggregate concrete showed an increasing trend. Considering a large amount of experimental data and the coupling effect of steel fiber contents and the maximum particle size of coarse aggregates, the Weibull distribution function was introduced to analyze the impact test results and predict the number of resistance to impact under different failure probabilities. The results showed that the number of blows of the recycled aggregate concrete followed a two-parameter Weibull distribution, and the estimated value of the number of resistance to impact for failure increased with the increase of the failure probability.

scholarly journals Particle Size Distribution Based Occurrence Features of Organic Components in Printing and Dyeing Wastewater Under a Treatment Process

2019 ◽  
Vol 118 ◽  
pp. 04009
Author(s):  
Yuan Li ◽  
Jie Liu ◽  
Yibiao Yu ◽  
Hao Zhu ◽  
Zheng Shen ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Reverse Osmosis ◽  
Treatment Process ◽  
Dyeing Wastewater ◽  
Wastewater Treatment Process ◽  
Printing And Dyeing Wastewater ◽  
Sedimentation Tank ◽  
The Relationship

A more detailed occurrence features of organic matters in the printing and dyeing wastewater, based on its particle size distribution (PSD) and along with a wastewater treatment process, was conducted to provide a support for advanced treatment. Results suggested that, (1) In the dyeing wastewater, the occurrence characteristic of COD was: soluble>supra colloidal>colloidal>settleable; However, for protein, the supra colloidal was dominant, followed by the soluble. The feature of the polysaccharide was consistent with COD’s. In the wastewater, 29.66% of COD could be attributed to proteins and 3.45% of the COD could be attributed to polysaccharides. (2) The relationship among the forms of COD in the primary sedimentation tank, aerobic tank, secondary sedimentation tank, and reverse osmosis-treated concentrated effluent was consistent, that was: soluble>colloidal>supra colloidal>settleable. (3) In the primary sedimentation tank, the settleable COD was almost completely removed; In the aerobic tank, the residual super colloidal COD was not much; After MBR-RO treatment, the COD in the reverse osmosis concentrated water was almost dissolved and only a little presented in other forms.

Recycling of Waste Concrete and Fly Ash for Recycled Aggregate Concrete: Fundamental Characteristics Evaluation

2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Waste Concrete

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.

A comparison of signal suppression and particle size distributions for ns- and fs-LA of metallic samples by LA-ETV-ICPMS

2017 ◽  
Vol 32 (10) ◽  
pp. 1980-1987
Author(s):  
Hale Ceren Yilmaz ◽  
Bodo Hattendorf
Keyword(s):  
Particle Size ◽  
Thermal Treatment ◽  
Graphite Furnace ◽  
Size Distributions ◽  
Electrothermal Vaporization ◽  
Particle Size Distributions ◽  
Signal Suppression

The influence of thermal treatment of laser-generated aerosols in a graphite furnace electrothermal vaporization (ETV) unit was investigated.

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