Sustainable Concretes – Through Reducing the Water Absorptivity to Improved Durability

2017 ◽  
Author(s):  
Róbert Figmig ◽  
Adriana Eštoková ◽  
Michaela Smoláková
Keyword(s):  
Wastewater Treatment Plants ◽  
International Standards ◽  
Mix Design ◽  
Environmental Aspects ◽  
Depth Of Penetration ◽  
Concrete Material ◽  
Chemical Attack ◽  
Binder Ratio ◽  
Maximum Water ◽  
Cast Products

Water absorptivity (WA) is one of the crucial parameters affecting the penetration of aggressive ions when concrete material is exposed to an aggressive environment and is closely linked with a depth of penetration of water under pressure into the concrete. Concrete used for prefabricated elements and structures as cesspits, manholes, pipe lines or parts of the wastewater treatment plants, has to meet a requirement for maximum water absorptivity of 6.0 wt. % in accordance with national and international standards. The article deals with a study of concretes’ water absorptivity of the pre-cast products for environmental purpose, where the exposure class XA (chemical attack) is required. The research is focused on reducing WA by using various modification of standard mix design (Portland cement, water, fine and coarse aggregate, plasticizer), e.g. by using different cement types, cementous supplementary additives, admixtures, finest aggregate particles or by reducing water/binder ratio. The concretes of various mix design modifications were compared with a reference concrete in relation to the standard. The economical and environmental aspects were also taken into consideration.

Influence of Asphalt Dust Waste Material in Mix Design for Self-Compacting Concrete

2017 ◽  
Vol 730 ◽  
pp. 473-478 ◽  
Author(s):  
Shahiron Shahidan ◽  
Isham Ismail ◽  
Muhammad Shafiq Syazwan Zulkarnaian ◽  
Norashidah Abd Rahman
Keyword(s):  
Mix Design ◽  
Waste Materials ◽  
Gravity Effect ◽  
Limited Information ◽  
Self Compacting Concrete ◽  
Green Concrete ◽  
Vibration Process ◽  
Binder Ratio ◽  
Alternative Solutions ◽  
Water Binder Ratio

Various studies on concrete have been conducted to utilize waste materials from different industries to produce sustainable green concrete. Adding asphalt dust waste (ADW) as a filler in the development of self-compacting concrete (SCC) is one of the alternative solutions. SCC is a high workability concrete that can flow under its own weight without vibration process and flows with gravity effect. However, there is limited information on the effect of ADW in the development of SCC. Therefore, this study is conducted to investigate the use of ADW in SCC in order to maximize its benefits in improving the workability of SCC. This experimental study was done to examine the effects of water binder ratio and amount of superplasticizer (SP) on the rheological and mechanical properties of the developed SCC. The results showed that the increase of w/b ratio and amount of SP will also improve the workability of SCC. It was found that the suitable percentages of ADW as a concrete filler are between 30% to 50%. In conclusion, the results showed that the optimum percentage of ADW in SCC mix design was 40% with a w/b ratio of 0.3 and 2% SP which yielded a compressive strength of 40.8 MPa.

Microscopic Analysis and Study of High-Performance Seawater All-Coral Concrete

2019 ◽  
Vol 815 ◽  
pp. 216-222
Author(s):  
Chao Chen ◽  
Jin Ming Liu ◽  
Yang Yang ◽  
Zhi Guo Guo
Keyword(s):  
Mechanical Properties ◽  
Natural Environment ◽  
High Performance ◽  
Work Performance ◽  
Room Temperature ◽  
Microscopic Analysis ◽  
Internal Curing ◽  
Mix Design ◽  
Binder Ratio ◽  
Water To Binder Ratio

The ocean islands are far from inland and the concrete sandstone aggregates are scarce. In this paper, high-performance seawater all-coral concrete was developed by seawater mixing and room temperature maintenance design, and by optimizing the water-to-binder ratio, regulating internal curing, changing auxiliary cementing materials and blending ratio, incorporating expansion agent, adjusting fiber blending, etc. Combined with the consideration of work performance and mechanical properties, the concrete self-shrinkage is adjusted to further optimize the mix design. The mechanical properties of the optimized high-performance seawater all-coral concrete were studied, and the relevant durability tests were carried out according to the natural environment characteristics of the island. This is of great significance to the construction of island projects, repair and construction, and construction of protective projects [1].

scholarly journals Mix-design and Properties of Mortars from Alkali-activated Fly Ashes Containing High Amounts of Unburned Carbon Matter

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Stefania Manzi ◽  
Andrea Saccani ◽  
Luca Baldazzi ◽  
Isabella Lancellotti
Keyword(s):  
Ad Hoc ◽  
Environmental Benefits ◽  
Mix Design ◽  
Unburned Carbon ◽  
Carbonaceous Matter ◽  
Fly Ashes ◽  
Fresh State ◽  
Binder Ratio ◽  
Alkali Activated ◽  
Promising Type

AbstractAlkali-activated materials are a promising type of binder candidate as a substitute to Portland cement. Fly ashes can be used as binder precursors giving higher environmental benefits. In the present research, fly ashes (Type F) containing different amounts of unburned carbonaceous matter have been used to formulate mortars. Serious problems concerning the workability in the fresh state have been found when high carbon content are reached. An attempt to avoid the preliminary treatments used to eliminate the unburned matter is carried out by exploiting different mix-design receipts obtained by changing the water/binder ratio, the ratio of the alkaline activators and using different types of superplasticizer additives. Data so far collected underline that a high amount of unburned carbonaceous matter can not only compromise the mechanical properties of the materials, but also the rheological ones and underline the necessity to develop ad hoc additives for this type of binders.

Influence of Blast Furnace Slag on the Mechanical Properties of High Performance Concrete

2013 ◽  
Vol 634-638 ◽  
pp. 2716-2719
Author(s):  
Wan Shin Park ◽  
Sung Ho Cho ◽  
Song Hui Yun ◽  
Jeong Eun Kim ◽  
Do Gyeum Kim ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Splitting Tensile Strength ◽  
International Standards ◽  
Binder Ratio ◽  
Furnace Slag

The characteristics of the compressive strength and splitting tensile strength according to replacement ratio of the blast furnace slag were found in this study. The blast furnace slag was utilizes as the concrete mix-material and then, these results were compared with the basis presented in the international standards. In this study, cylinder made of concrete with water/binder ratio 0.34 and blast furnace slag replacement rate of 10%, 30%, 50%, and 70% were prepared to measure the compressive strength and spiting tensile strength. Test results indicate that The 28 days and 91 days compressive strength is affected by blast furnace slag replacement except specimen BS30 and the splitting tensile strength in specimen BS series is slightly larger than that of OPC except specimen BS 30.

Proportion Design of Autoclaved Cement Concrete Based on High Strength

2011 ◽  
Vol 391-392 ◽  
pp. 161-164
Author(s):  
Tie Quan Ni ◽  
Chang Jun Ke ◽  
Li Zhang
Keyword(s):  
Coarse Aggregate ◽  
High Strength ◽  
Orthogonal Test ◽  
Mineral Admixture ◽  
Mix Design ◽  
Hydration Reaction ◽  
Cement Concrete ◽  
Binder Ratio ◽  
Four Levels ◽  
Water Binder Ratio

According to the particularity of the autoclaved cement concrete that partial aggregate could participate in hydration reaction in the process of autoclaving, the optimal gradation of coarse aggregate and the optimal slurry aggregate ratio is studied, and the effect of water reducing agent for fluidity of cement paste is also studied. The optimized mix design of autoclaved cement concrete based on high strength (compressive strength and flexural strength) is done by orthogonal test with four factors (water-binder ratio, type of mineral admixture, amount and sand ratio) and four levels.

THE INFLUENCE OF BAMBOO REINFORCEMENT AND ADDITION OF FIBERS ON HOLLOW BEAMS

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Faisal Ananda ◽  
Hendra Saputra ◽  
Armada Sukri
Keyword(s):  
Tensile Strength ◽  
Initial Crack ◽  
Steel Reinforcement ◽  
Mix Design ◽  
Concrete Material ◽  
Artistic Value ◽  
Concrete Mix Design ◽  
Concrete Mix ◽  
Hollow Beams ◽  
Bamboo Reinforcement

The development of the artistic value of a building with reinforced concrete material continues to grow, one of which burrows the pipeline so as unexposed so that the condition of a building looks beautiful. This condition makes a weakening of the strength of concrete. As for the weakness of the concrete caused by a small crack due to deflection or the other anticipated by the addition of fiber one of the rebar tie wire (bendrat). Based on this condition, the beam testing was done with size by 150mm x 200mm x 1200mm with using one-point loading. Concrete mix design using SNI 03-2834-2000. The load obtained without fibers using the steel reinforcement by 12.9% greater than the use of bamboo reinforcement. This is because the tensile strength of bamboo is smaller than the tensile strength of iron. Likewise, on the beam that added fiber as much as by 2% on the bamboo reinforcement, there is a difference of loading is smaller than the steel reinforcement by 25%. The interesting result is found in the 0.5 inch diameter beam which has an increase in load with the initial crack conditions close to the same as the beam without a hole.

scholarly journals Partial Replacement of Fine Aggregate Using Water Purification Sludge in Producing CLSM

2019 ◽  
Vol 11 (5) ◽  
pp. 1351
Author(s):  
Chao-Wei Tang ◽  
Chiu-Kuei Cheng
Keyword(s):  
Water Purification ◽  
Large Scale ◽  
Mix Design ◽  
Engineering Properties ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Scale Production ◽  
Binder Ratio ◽  
Water Binder Ratio ◽  
Slag Content

This study investigated the mix design and engineering properties of controlled low-strength material (CLSM) by partial replacement of fine aggregate using water purification sludge (WPS). First, an investigation was performed at laboratory scale to assess the effects of the constituent materials and their quantities on the properties of the resulting CLSM. The Taguchi method of experimental design was used to determine optimal parameters for the mix design of CLSM. The parameters investigated included sludge content, water–binder ratio, slag content, accelerator agent content, and coarse aggregate content. Then, a cost analysis of a large-scale production CLSM containing WPS in a commercially available ready-mix concrete batching plant was performed. The results indicated that the water–binder ratio was the most significant factor that contributed to the target value (17.5 cm) of the tube flow of the mixture. The main contributions of experimental factors were water–binder ratio (78.00%), slag content (18.71%), accelerator agent content (2.41%), and sludge content (0.88%). Moreover, the strength of mixtures containing WPS was lower than that of mixtures without WPS. In particular, when the replacement percentage of fine aggregates with WPS was more than 20%, the strength was significantly reduced. The material cost per cubic meter of CLSM containing WPS is about NT$297.42 lower than that of ordinary CLSM, which can reduce the cost by 17.53%.

scholarly journals Mechanical and Durability Evaluation of Concrete with Sulfate Solution Corrosion

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Feng Ming ◽  
You-sheng Deng ◽  
Dong-qing Li
Keyword(s):  
Damage Model ◽  
Power Laws ◽  
Sulfate Solution ◽  
Strength Development ◽  
Depth Of Penetration ◽  
Damage Development ◽  
Concrete Construction ◽  
Concrete Material ◽  
Sulfate Ions ◽  
Chemical Corrosion

Concrete material has been a choice for the construction structures, even in the cold regions and saline zone. However, these environmental factors have critical damaging effect on the concrete characters. Consequently, this damage will decrease the servicing time of the concrete construction within this environment. In order to evaluate the durability of concrete, the behavior of concrete specimens under the sulfate solution corrosion attacks was studied in this presented work. Two groups of the specimens were immersed into the sulfate solutions with a concentration of 10% and 20%, respectively. The strength development of the specimens under different immersing time was studied. Based on Fick’s law, a steady diffusion equation for sulfate ions in concrete was presented, and the depth of penetration of the attacking sulfate ions was also determined. Based on the depth of penetration and the definition of damage, a damage model for concrete material is developed and a new equation (strength-time) describing the chemical corrosion concrete material is proposed. Results show that the suggested analytical methods can quantify the damage process of concrete under sulfate attack, and the power laws damage developing formula can be used to describe the damage development of the concrete construction subjected to chemical corrosion.

scholarly journals Effect of Alccofine on the Properties of Concrete Incorporating Steel Fibers

2020 ◽  
Vol 9 (5) ◽  
pp. 44-47
Keyword(s):  
Strength Properties ◽  
Steel Fibers ◽  
Mix Design ◽  
Morphological Properties ◽  
Conventional Concrete ◽  
Concrete Mix Design ◽  
Morphological Studies ◽  
Concrete Mix ◽  
Binder Ratio ◽  
Water Binder Ratio

This paper deals with the investigation of concrete containing varying replacement percentages of Alccofine and conjointly Alccofine and different proportions of steel fibers with aspect ratio 50 to investigate mechanical and morphological properties. The replacement levels of Alccofine was chosen as 5% to 15% with 5% increment and steel fibers of 0.5% to1.5% with an increment of 0.5% by volume of concrete. Mix design was done by using British D.O.E method, fixing water binder ratio as 0.45. Results indicated that concrete replaced with Alccofine in addition of steel fibers increased the compressive and flexural strength of concrete. The maximum strength was obtained for the concrete mix containing 15% Alccofine and 1.5% circular crimped steel fibers. Morphological studies indicated the excess C-S-H gel for concrete mixes containing Alccofine as compared to conventional concrete. Hence, it can be culminated that Alccofine and addition of steel fibers increases the strength properties and crack resistant strength of concrete.

scholarly journals Odour measurement in wastewater treatment plant using both European and Japanese standardized methods: correlation and comparison study

2016 ◽  
Vol 18 (4) ◽  
pp. 728-733 ◽  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
International Standards ◽  
Municipal Wastewater Treatment ◽  
Odour Concentration ◽  
High Concentrations ◽  
The University

<p>Odours discharged from wastewater treatment plants generally cause severe damage to locals. When facility odors affect air quality and cause citizen complaints, an investigation of those odours may require using standardized scientific methods. Odour intensity is one of the main odour characterization parameter, and represents an important sensory indicator of environmental odours.</p> <p>Presently, different international standards have been developed for the measurement of odours. Main consolidated methods are the measurement of odour index assessed by panelists, standardized in Japan and developed there more than 40 years ago; and the measured of odour concentration by dynamic olfactometer according to European standard EN13725:2003.</p> <p>In this study odour samples were collected on a municipal wastewater treatment plant to investigate the relationship between odour index assessed by Japanese standard methods and odour concentration measured with dynamic olfactometry. A monthly sampling and relative odour measurement were carried out for consecutive 8 months at the Laboratory of the Sanitary Environmental Engineering Division (SEED) at the University of Salerno (Italy).</p> <p>Results show a strong linear correlation between the two investigated odour measurement methods, in the case of the measurement of high concentrations. While at lower odour concentrations were observed a difference between the two methods.</p>

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