The Effect of Cassava Starch on the Durability Characteristics of Concrete

2020 ◽  
Vol 14 (1) ◽  
pp. 289-301
Author(s):  
Daniel Oni ◽  
John Mwero ◽  
Charles Kabubo
Keyword(s):  
Cement Hydration ◽  
Research Work ◽  
Cassava Starch ◽  
Chloride Penetration ◽  
Hardened Concrete ◽  
Sulphate Attack ◽  
Marine Structures ◽  
Durability Properties ◽  
Chloride Attack ◽  
Starch Gel

Background: Concrete is a common material used in the construction of marine structures, such as bridges, water treatment plants, jetties, etc. The use of concrete in these environment exposes it to attack from chemicals like sulphates, chlorides and alkaline, thereby causing it to deteriorate, and unable to perform satisfactorily within its service life. Hence, the need to investigate the durability properties of concrete has become necessary especially when admixtures are used to modify some of its properties. Objective: This research work investigates the effect of Cassava Starch (CS) on the durability characteristics of concrete. Methods: The durability properties investigated in this work are water absorption, sorptivity, resistance to sulphates, sodium hydroxides and chloride penetration. The specimens were prepared by adding CS by weight of cement at 0.4, 0.8, 1.2, 1.6 and 2.0% respectively. The concrete specimens were cured for 28 days, tested for compressive strength before ponding in ionic solutions of sodium hydroxide, sulphuric acid and sodium chloride. Six (6) concrete mixes were prepared, five of which were used to evaluate the effect of CS on the durability characteristics of concrete. Results: The slump values reduced with the increasing dosage of CS due to the viscous nature of the CS paste. Generally, the addition of CS in concrete tends to improve the resistance of concrete to sulphate and chloride attack due to the ability of the muddy-like starch gel to block the pore spaces of hardened concrete, hence, reduces the rate at which water and other aggressive chemicals penetrate the concrete. In addition, the retarding ability of CS impedes the formation of mono-sulphate aluminates during cement hydration, thereby making the concrete less susceptible to sulphate attack. Conclusion: The addition of CS to concrete by weight of cement generally improved the durability characteristics of concrete, while the relative performances of the concrete mixes showed that CS 2.0 gave a better resistance to chloride penetration and sulphate attack.

scholarly journals Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3

2020 ◽  
Vol 9 (1) ◽  
pp. 998-1008
Author(s):  
Guo Li ◽  
Zheng Zhuang ◽  
Yajun Lv ◽  
Kejin Wang ◽  
David Hui
Keyword(s):  
Cement Hydration ◽  
Mercury Intrusion Porosimetry ◽  
Hardened Concrete ◽  
Optimal Dosage ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Carbonation Depth ◽  
X Ray ◽  
Chloride Resistance

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

A sustainable approach to optimum utilization of used foundry sand in concrete

2018 ◽  
Vol 25 (5) ◽  
pp. 927-937 ◽  
Author(s):  
Khuram Rashid ◽  
Sana Nazir
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Research Work ◽  
Hardened Concrete ◽  
Prediction Formula ◽  
Foundry Sand ◽  
Foundry Sands ◽  
Fine Aggregates ◽  
Optimum Utilization ◽  
Conservation Of Natural Resources

AbstractConservation of natural resources, healthy environments, and optimal utilization of waste materials are intimate needs of the present time, and this research work was carried out to fulfill these needs. In this experimental and analytical study, concrete was prepared by replacing natural fine aggregates with two types of used foundry sands by 10%, 20% and 30% (by volume). The properties of fresh and hardened concrete were investigated and compared with a replacement amount of fine aggregates from 0% to 30%. Compressive strength was evaluated after 7, 28 and 63 days of moist curing. Along with compressive strength, the modulus of elasticity was also investigated and a reduction in compressive strength and modulus of elasticity was observed with the increase in the amount of used foundry sand. A prediction formula was proposed to predict the compressive strength, and verified by current experimental observations and also with a large database that was also established in this work. The prediction formula may be considered as very helpful for predicting the potential of using used foundry sand as an aggregate in concrete.

A sustainable approach in using construction and demolition waste materials in concrete

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pritish Gupta Quedou ◽  
Eric Wirquin ◽  
Chandradeo Bokhoree
Keyword(s):  
Flexural Strength ◽  
Pulse Velocity ◽  
Chloride Penetration ◽  
Construction And Demolition Waste ◽  
Waste Materials ◽  
Hardened Concrete ◽  
Depth Of Penetration ◽  
Demolition Waste ◽  
Continuous Increase ◽  
Content Type

Purpose The purpose of this paper is to investigate the potential use of construction and demolition waste materials (C&DWM) as an alternative for natural fine aggregates (NFA), in view to solve the disposal problems caused due to landfills. In addition, to evaluate its suitability as a sustainable material, mechanical and durability properties have been performed on different proportions of concrete blending and the results recorded were compared with the reference concrete values. Design/methodology/approach In this research, the NFA were replaced at the proportion of 25%, 50%, 75% and 100% of C&DWM with a constant slump range of 130 mm–150 mm. This parameter will assess the consistency of the fresh concrete during transportation process. The characteristics of the end product was evaluated through various tests conducted on hardened concrete samples, namely, compressive strength, flexural strength, depth of penetration of water under pressure, rapid chloride penetration test, carbonation test and ultrasonic pulse velocity (UPV) test. All results recorded were compared with the reference concrete values. Findings The results demonstrated that the use of C&DWM in concrete portrayed prospective characteristics that could eventually change the concept of sustainable concrete. It was noted that the compressive and flexural strength decreased with the addition of C&DWM, but nevertheless, a continuous increase in strength was observed with an increase in curing period. Moreover, the increase in rapid chloride penetration and decrease in UPV over time period suggested that the concrete structure has improved in terms of compactness, thus giving rise to a less permeable concrete. The mechanical tests showed little discrepancies in the final results when compared to reference concrete. Therefore, it is opined that C&DWM can be used effectively in concrete. Originality/value This study explores the possible utilisation of C&DWM as a suitable surrogative materials in concrete in a practical perspective, where the slump parameter will be kept constant throughout the experimental process. Moreover, research on this method is very limited and is yet to be elaborated in-depth. This approach will encourage the use of C&DWM in the construction sector and in the same time minimise the disposal problems caused due to in landfills.

scholarly journals Evaluation of admixture effect on strength and durability properties of concrete - a critical review

2018 ◽  
Vol 7 (2.1) ◽  
pp. 28
Author(s):  
Mahesh V ◽  
Hemalatha Chemalapati ◽  
Vani A ◽  
Sreenivasulu Dandagala
Keyword(s):  
Research Work ◽  
Bentonite Clay ◽  
Waste Material ◽  
Cow Dung ◽  
Waste Products ◽  
Durability Properties ◽  
Stone Dust ◽  
The World ◽  
Egg Shell ◽  
Strength And Durability

The present paper is focused on the study of admixture effect on strength and durability properties of concrete. In this study selected admixtures bentonite clay, coconut shell, cow dung ash, crushed rubber, egg shell, glass powder, groundnut shells, rich husk, stone dust, sugar bagasse etc., research papers has been reviewed. Inspite of several usage of waste, presently millions of tons are produced every year and remain unused all around the world and causes serious environment problems. Utilization of waste products all over the world has become challenging task for civil engineers. High costs of cements are not economical for all the types of construction works. Therefore, it is necessary to utilize the locally available materials for improving the properties of concrete in the field of construction industry. The usage of different waste material for the improvement of concrete properties has drawn much attention to the researchers. Moreover, several researchers were made an investigation on laboratory tests on partial and fully replacement of cement, sand, aggregate in concrete and various properties like workability, compressive strength, and density are studied. Based on the research work carried out several researchers we can conclude that the utilization of different usage of waste material as resources and prevents environmental pollution. It is also observed that waste materials can be used as an alternate material for the better improvement of strength and durability properties of concrete.

Performance of Concrete Made with Recycled Aggregates from Portuguese CDW Recycling Plants

2014 ◽  
Vol 634 ◽  
pp. 193-205 ◽  
Author(s):  
Miguel Bravo ◽  
Jorge de Brito ◽  
Jorge Pontes ◽  
Luís Evangelista
Keyword(s):  
Fresh Concrete ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Concrete Compressive Strength ◽  
Performance Loss ◽  
Experimental Campaign ◽  
Significant Performance ◽  
Chloride Penetration Resistance

The objective of this research is the production of concrete with recycled aggregates (RA) from various CDW plants around Portugal. The influence of the RA collection location and consequently of their composition on the characteristics of the concrete produced was analysed. In the mixes produced in this research RA from five plants (Valnor, Vimajas, Ambilei, Europontal and Retria) were used: in three of them coarse and fine RA were analysed and in the remaining ones only coarse RA were used. The experimental campaign comprised two tests in fresh concrete (cone of Abrams slump and density) and eight in hardened concrete (compressive strength in cubes and cylinders, splitting tensile strength, modulus of elasticity, water absorption by immersion and capillarity, carbonation and chloride penetration resistance). It was found that the use of RA causes a quality decrease in concrete. However, there was a wide results scatter according to the plant where the RAs were collected, because of the variation in composition of the RA. It was also found that the use of fine RA causes a more significant performance loss of the concrete properties analysed than the use of coarse RA.

Investigation and Application of High Performance Concretes

2010 ◽  
Vol 659 ◽  
pp. 517-521
Author(s):  
Viktória Sugár ◽  
Márton Takács ◽  
Vilmos Ovári
Keyword(s):  
Bulk Density ◽  
High Performance ◽  
Research Work ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
Concrete Technology ◽  
Normal Concrete ◽  
Air Content ◽  
The Mean

Recent research work of the authors is dealing with preparing, investigation and application of high performance concretes (HPC) produced by the mean of results of modern concrete technology. These special types of concrete have one or more outstanding properties conversely the normal concrete. This article is focusing on the results of the experiments regarding self compacting concrete (SCC). During the investigation, effects of the fine-graded fraction was studied, which is indispensable component of the SCC. The effects of bulk density, consistency, air content, compressive strenght were analysed on fresh and hardened concrete.

scholarly journals Single-Step Ethanol Production from Raw Cassava Starch Using a Combination of Raw Starch Hydrolysis and Fermentation, Scale-Up from 5-L Laboratory and 200-L Pilot Plant to 3,000-L Industrial Fermenters

2020 ◽  
Author(s):  
Morakot Krajang ◽  
Kwanruthai Malairuang ◽  
Jatuporn Sukna ◽  
Krongchan Rattanapradit ◽  
Saethawat Chamsart
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Scale Up ◽  
Research Work ◽  
Cassava Starch ◽  
Single Step ◽  
Starch Hydrolysis ◽  
Yield Coefficient ◽  
Raw Starch ◽  
Raw Starch Hydrolysis

Abstract Background: A single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing (CBP) technologies, this research work was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. This resulted high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. The yields of ethanol concentration are comparable with those in the commercial industries that use molasses and hydrolyzed starch as the raw materials. Results: Before single-step ethanol production, the studies of raw cassava starch hydrolysis by a granular starch hydrolyzing enzyme, StargenTM002, were carefully conducted. It successfully converted 80.19% (w/v) of raw cassava starch to glucose at a concentration of 176.41 g/L with a productivity of 2.45 g/L/h when the raw starch was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. A single-step ethanol production at 34 °C in a 5-L fermenter showed that S. cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, p of 81.86 g/L (10.43% v/v) with a yield coefficient, Y p/s of 0.41 g/g, a productivity or production rate, r p of 1.14 g/L/h with an efficiency, Ef of 71.44%. The scale-up experiments of the single-step ethanol production using this method, from the 5-L fermenter to the 200-L fermenter and further to the 3,000-L industrial fermenter were successfully achieved with essentially good results. The p, Y p/s , r p , and Ef values of the 200-L scale were 80.85 g/L (10.23% v/v), 0.41 g/g, 1.12 g/L/h and 72.47% , respectively ; of the 3,000-L scale were 70.74 g/L (9.01% v/v), 0.34 g/g, 0.98 g/L/h and 59.82% , respectively. Because of using raw starch, the major by-products of all the three scales were very low; glycerol lactic acid and acetic acid, in ranges of 0.94-1.14%, 0.046-0.052%, 0-0.059% (w/v), respectively, where are less than those values in the industries. Conclusions: This single-step ethanol production using a combination of raw cassava starch hydrolysis and fermentation of the three fermentation scales here is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.

scholarly journals Durability Performance of Concrete (M-45) Fine Aggregate Partially Replaced with Crushed Waste Glass

2020 ◽  
Vol 9 (4) ◽  
pp. 1818-1822
Keyword(s):  
Research Work ◽  
Acid Resistance ◽  
Chloride Penetration ◽  
Waste Glass ◽  
Engineering Properties ◽  
Fine Aggregate ◽  
Concrete Durability ◽  
Reinforcing Bars ◽  
Chemical Attack ◽  
Acid Environment

Durability of concrete is as the ability to resist weathering action, chemical attack, and abrasion while giving the desired engineering properties. Concrete require different degrees of durability depending on the exposure environmental conditions. The retrogression of concrete structures is due to effect of attrition of reinforcing bars which is occurred due to the chloride incursion.so it is necessary to study the concrete durability nature before making its usage in present construction. The present research is focused on studying the effect of using sustainable material in concrete preparation. To know the effective usage of crushed waste glass in concrete and significance in Durability properties for different replacements was studied .The present research work was done using materials like cement, Fine aggregate, coarse aggregate, waste crushed glass, super plasticizer in order to know that at which combination of mix there will be optimum effect on properties of concrete. In this research Waste crushed glass was used as fractions of 10%,20%,30% and 40% by weight of crushed glass used. The durability tests to test resistance against acid environment chloride penetration and abrasion resistance tests are performed. The optimum value of acid resistance was observed when fine aggregate was replaced with 30% of fine aggregate with crushed waste glass, less abrasion loss at 30% replacement and chloride penetration also effective at 30% replacement.

scholarly journals PROPERTIES OF CEMENT-FLY ASH MIXTURES WITH SUBSTANDARD FLY ASH AS A PARTIAL CEMENT AND FINE AGGREGATE REPLACEMENT

2021 ◽  
Vol 11 (3) ◽  
pp. 71-88
Author(s):  
Piseth Pok ◽  
Parnthep Julnipitawong ◽  
Somnuk Tangtermsirikul
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Sulfate ◽  
Chloride Penetration ◽  
The Other ◽  
Fine Aggregate ◽  
Carbonation Depth ◽  
Cement Replacement ◽  
Durability Properties ◽  
Compressive Strength Of Concrete

This research investigated the effects of using a substandard fly ash as a partial cement and/or fine aggregate replacement on the basic and durability properties of cement-fly mixtures. Experimental results showed that utilizing the substandard fly ash led to increase in water requirement and autoclave expansion of pastes. The strength activity indexes of the substandard fly ash passed the requirements of TIS 2135 and ASTM C618. Utilization of the substandard fly ash as cement replacement led to higher expansion of mortar bars stored in water and sodium sulfate expansion as compared to that of the OPC mixture. However, sodium sulfate resistance of mortar mixtures improved when utilizing the substandard fly ash as sand replacement material. The compressive strength of concrete at all ages was higher with the increase of the content of the substandard fly ash as sand replacement material. When the substandard fly ash was used as cement replacement material in concrete, the carbonation depth increased. On the other hand, the use of the substandard fly ash as sand replacement material decreased the carbonation depth of the concrete. Utilization of the substandard fly ash, both to replace cement and/or fine aggregate, reduced the rapid chloride penetration of the concrete.

Mechanical and Durability Analysis of Recycled Materials

2021 ◽  
Vol 882 ◽  
pp. 228-236
Author(s):  
Anamika Agnihotri ◽  
Ajay Singh Jethoo ◽  
P.V. Ramana
Keyword(s):  
Research Work ◽  
Waste Glass ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Split Tensile Strength ◽  
Recycled Materials ◽  
Durability Properties ◽  
Substitution Level ◽  
Durability Analysis ◽  
Concrete Mix

The mechanical and durability properties were best at 45% GGBS and 5% Waste Glass with 0.4 water/cement ratio. The recycled materials implemented for mix proportion were waste glass provided considerably to enhance its properties when added with GGBS. In most of the research work, the effect of WG and GGBS in concrete as a partial substitution of fine aggregate and cement individually is analyzed. Previous studies only show the individual impact of these concrete recycled materials on mechanical and durability properties. In the present study, an exact optimum substitution level of cement by GGBS (15 – 60% at an increment of 15%) and fine aggregate by the waste glass (5 – 20% at an increase of 5%) combined for OPC concrete mix. Mechanical (compressive strength, split tensile strength and flexural strength) and microstructural properties (FESEM) were observed on the combination of waste glass and GGBS concrete mix.

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