Strength Self Research Articles

High Strength Self Compacting Concrete Beams under Flexure.

High Strength Self Compacting Concrete Beams under Flexure.

Correlation of Static and Dynamic modulus of Elasticity for Different SCC Mixes

For an existing structure static modulus of elasticity of concrete cannot be determined but dynamic modulus of elasticity can be determined by using non destructive testing (NDT) method. The value obtained by NDT cannot match exactly with the static modulus of elasticity but have certain relationship with it. Hence, correlation is required. Self compacting concrete is growing trend in advanced countries. Therefore to know the quality of SCC used in the structures it was proposed to study the relation between the static and dynamic modulus of elasticity of different grades, mixes of SCC. The objective of this study is to compare the static and dynamic modulus of elasticity and the strength of self compacting concrete using silica fume and fly ash. A simple mix design for SCC Proposed by Nan-su method has been used for fixing the trial mixes. DOI: 10.17762/ijritcc2321-8169.1507114

An Experimental Study on Impact Strength of Self Compacting Concrete

An Experimental Study on Impact Strength of Self Compacting Concrete

CHARACTERISTICS OF HIGH PERFORMANCE SELF COMPACTING CONCRETE INCORPORATING FLY-ASH AND METAKAOLIN

This paper presents the experimental studies οn strength & Durability prοperties οf High Perfοrmance Self Cοmpacting Cοncrete (HPSCC) made with manufactured sand and as partial replacement οf cement by Mineral Admixture (Flyash, Metakaοlin). The mix design fοr HPSCC was arrived as per the guidelines οf Eurοpean Federatiοn οf Natiοnal Assοciatiοn representing fοr Cοncrete (EFNARC). The Rheοlοgy prοperties was determined by tests as filling ability, passing ability and segregatiοn resistance including pH and Temperature. Strength prοperties was determined by Cοmpressive, split tensile, Flexural strength and Yοung’s Mοdulus were examined. And durability prοperties were determined by Rapid Chlοride Penetratiοn Test (RCPT) are carried οut. Keywοrds: High perfοrmance self-cοmpacting Cοncrete, Metakaοlin, Flyash, Manufactured sand. --------------------------------------------------------------------***------------------------------------------------------------------

Behavior of High Strength Self Compacted Hollow Section Reinforced Concrete Beams under Pure Torsion

In this work, an experimental study has been conducted to investigate the behavior of high strength self-compacted concrete hollow beams under pure torsion.In this work, the beams were implemented and tested under pure torsion load. A total of six beams were tested. All beams were of the same cross section, the same length, the same concrete mixture and quality control. All beams were of external dimensions (300x300mm) and the hollow dimensions (180 x180mm) and all the concrete beams have the same number of main reinforcement 4Ф12 at the top and 4Ф12 at the bottom, the main variable is the stirrups spacing to investigate the effect of stirrups amount on improving of hollow reinforced concrete beams resistance against torsional moments.The six beams were subjected to pure torsion by using fabricated test machine to enable the application of the mentioned pure torsion load.Experimental results showed that, many structural properties of the beams are improved, by decreasing the stirrups spacing. Highest improvement achieved for ultimate torsional moment (Tu) followed by cracking torsional moment (Tcr) and then by angle of twist (O) while the improvement of beam's concrete strain (e) came at last.The percentage of improvements of the mechanical properties of the beams due to decrease of the stirrups spacing according to the reference beam is: For Tu ranges between (25.7-254.3) %. For Tcr ranges between (25-200) %. For O ranges between (23.3-76.0) %. For e (29.0-50.2) %.The considerable increase in O and e before failure makes the increase of stirrups preferable for safe life and attaining attention.

Behavior of High Strength Self Compacted Hollow Section Reinforced Concrete Beams under Pure Torsion

In this work, an experimental study has been conducted to investigate the behavior of high strength self-compacted concrete hollow beams under pure torsion.In this work, the beams were implemented and tested under pure torsion load. A total of six beams were tested. All beams were of the same cross section, the same length, the same concrete mixture and quality control. All beams were of external dimensions (300x300mm) and the hollow dimensions (180 x180mm) and all the concrete beams have the same number of main reinforcement 4Ф12 at the top and 4Ф12 at the bottom, the main variable is the stirrups spacing to investigate the effect of stirrups amount on improving of hollow reinforced concrete beams resistance against torsional moments.The six beams were subjected to pure torsion by using fabricated test machine to enable the application of the mentioned pure torsion load.Experimental results showed that, many structural properties of the beams are improved, by decreasing the stirrups spacing. Highest improvement achieved for ultimate torsional moment (Tu) followed by cracking torsional moment (Tcr) and then by angle of twist (Ø) while the improvement of beam's concrete strain (ε) came at last.The percentage of improvements of the mechanical properties of the beams due to decrease of the stirrups spacing according to the reference beam is: For Tu ranges between (25.7-254.3) %. For Tcr ranges between (25-200) %. For Ø ranges between (23.3-76.0) %. For ε (29.0-50.2) %.The considerable increase in Ø and ε before failure makes the increase of stirrups preferable for safe life and attaining attention.

Porosity, Pore Size and Compressive Strength of Self Compacting Concrete Using Sea Water

Indonesia is the largest archipelago in the world, so it has much territory that the quality of the source water is not qualified as mixing water in construction. Besides, construction of concrete in areas that are likely quantity of water or fresh water is very minimal or even nothing then the sea water cannot be avoided in mixing concrete. This research was an experimental study, the samples for compressive strength test are cylindrical premises size of 10 mm×20mm. The porosity relation, compressive power, age and model of porosity relationship with SCC concrete compressive strength which using sea water is discussed in this paper. Compressive strength testing is following the standard ASTM 39/C 39-99. Universal Testing Machine (UTM) was used in the testing of compressive strength. Test specimen for porosity created by taking part of the cylinder and then slashed with a size of approximately 2cm×3cm with a 0.003mm thick. The type and pore size and porosity were analyzed by using a polarizing petrography microscope Olympus BX 51-P. The result of research was increased the compressive strength and density of microstructures in line with the decrease in porosity and pore size of concrete and concrete age. Compressive strength relations (σss) and porosity (pss) the SCC used sea water can be approximated equation σss = σo (1-p)K, with σo = 119.6 and K = 7.502.

Normal Strength Self Compacting Concrete with Supplementary Cementitious Bagasse Ash and Rice Husk Ash

Normal Strength Self Compacting Concrete with Supplementary Cementitious Bagasse Ash and Rice Husk Ash

Mechanical strengths of self compacting concrete containing sawdust-ash and naphthalene sulfonate

The present research work is on the effect of sawdust ash (SDA) on the mechanical strengths of self compacting concrete (SCC) using naphthalene sulfonate (NS) as a plasticizer. Experiments on compressive, flexural and splitting tensile strengths are conducted and the data analyzed using the Minitab 15 software. The results showed that SDA can defer the reaction of cement hydration and prolong the setting times of cement paste. This was very much pronounced on the flexural and splitting tensile strengths at 90 days of curing which are 36 % and 33 % higher than the control strengths, respectively. The study has proposed strength relations of mortar compressive strength with the flexural and splitting tensile strengths and these are, 5 and 7 times respectively. The flexural strength is 1.5 times that of the splitting tensile. Finally, linear models were developed on these relationships.

Cognitive Competency of Filipino Nurses Working in Some Hospitals of Taif City , Kingdom of Saudi Arabia

Background:Nurses give care to diverse client population, which necessitates that, they should be culturally competent. Competence in cross cultural practice is a process requiring experience and continued interest in learning and in sharpening cultural assessment and communication skills. Objectives: Toinvestigate the cognitive competency of Filipino nurses working in five hospitals at Taif City, Kingdom of Saudi Arabia. The study evaluates strength of self-efficacy perception ofthenurses, on the cognitive constructs and the difference among the strength of self-efficacy perception of the nurses when grouped according to their demographic profiles. Methods:Transcultural Self-Efficacy Tool (TSET) Kit was used to measure the cognitive competency of three hundred and seven respondent Filipino nurses working in five hospitals of TaifCity. Results:The strength of self -efficacy perceptions of the nurses within the cognitive constructs shows that the five highest means score dealt with “safety”, “hygiene, “Informed consent, “pain relief and comfort” and “life support and resuscitation” while the five lowest scores dealt with “Health History and Interview”, “Sexuality”, “Birth”, “Pregnancy” and Diagnostic Test. The differences among the strength of self -efficacy perception of the nurses on the cognitive construct when grouped according to seven demographic profiles shows that only three of the demographics were different in some of the cognitive construct variables. These were work setting, department and preferred position Implications:The findings of the present study suggest in-service educational training to all nurses on transcultural nursing to enhance their cultural competencies.In addition, Arabic Language training is recommended as one of the requirements for new nurse applicants.

Concrete mix design for high strength self-compacting concrete using metakaolin

Metakaolin is a highly reactive pozzolanic admixture and has got significant potential for the development of concrete composites such as High Strength High Performance Concrete (HSHPC) and self compacting concrete (SCC), if appropriately designed. However, for obtaining the required performance in any of these concrete composites, metakaolin should be properly proportioned so that the resulting concrete would satisfy both the strength and performance criteria requirements of the structure. The present work is an effort towards obtaining a new mix methodology for the design of high strength self compacting metakaolin concretes based on the efficiency concept. The methodology has been successfully verified through a proper experimental investigation and the self compacting metakaolin concretes were evaluated for their self compactability and strength characteristics. The results indicate that the proposed method can be capable of producing high strength SCC of about 120MPa.

Effect of w/c ratio on workability and mechanical properties of high strength Self Compacting Concrete (M70 grade)

Effect of w/c ratio on workability and mechanical properties of high strength Self Compacting Concrete (M70 grade)

Effect of w/c ratio on workability and mechanical properties of high strength Self Compacting Concrete (M70 grade)

This paper presents the results of an experimental research on the workability and mechanical properties of self-compacting concrete. The work focused on concrete mixes having Water/Cement ratios of 0.23, 0.24, 0.25, 0.26 and 0.27, with a Packing Factor of 1.12. The Concrete mixes contains different proportions of GGBS, Super plasticizers, water binder ratios and constant proportions of Cement, Micro Silica, VMA, Coarse aggregate and Fine aggregate for different Water Cement ratios. The percentage of Micro Silica added is 7% for all mixes. The mix proportions are obtained on the basis of NAN-SU mix design. All the mixes contain Cement of 574 kg/m 3 but with different total binder content. The workability tests performed in this research were as per EFNARC. Based upon the experimental results, for water cement ratio 0.25 fresh and hardened state properties of high strength self-compacting concrete are moderate.

AN EXPERIMENTAL STUDY ON DURABILITY OF HIGH STRENGTH SELF COMPACTING CONCRETE (HSSCC)

The basic philosophy in the construction of every sis it should perform its intended function s successfully through the expected and anticipated life time, irrespective of external exposure conditions. The ability of the c oncrete is to resist and withstand any environmental conditions that may result in ear ly failure or severe damages and it is a major conc ern to the engineering professional. Out of all the deteriorating agents a cid attack is one of the phenomena that plays a vit al role in disintegrating concrete structures depending on the type and concentration of the acid. Certain acids are harmless. The presen t investigation focused on the effect of H 2 So 4 and HCL on High Strength Self Compacting Concrete.

DESIGN OF SCC MIXES BASED ON CEMENT – SP COMPATIBILITY STUDIES

In this work 4 superplasticizers were used and on t he basis of the workability test on cement paste tw o SP’s were selected for further studies and to compare their effects on mortar prop erties such as workability, compressive strength, w ater reduction and tensile strength. Two different mortar mixes (1:1.5 & 1:2) were tested for three values of w/c ratio (0.3, 0.3 5, and 0.4) for varying SP dosage i.e. from 0.6 to 2%. This paper presents an experim ental investigation on strength aspects such as com pressive, and split tensile strength of self compacting concrete containing fly ash and workability tests (slump flow, T 500mm , V-Funnel and T 5min ) are carried out. The methodology adopted is that Portland cement is replaced by 0%, 35% and 50% of fly ash using two ty pes of superplasticizers (SNF, PCE) and performance is measured and compared . Further Design of Self Compacting Concrete by repla cing Fly ash is proposed and the studies on fresh a nd hardened properties were conducted. The results showed that PCE type Superpl asticizer is performing better than SNF type in ter ms of workability.

Can you tickle yourself if you swap bodies with someone else?

The effect of the body transfer illusion on the perceived strength of self- and externally-generated "tickle" sensations was investigated. As expected, externally generated movement produced significantly higher ratings of tickliness than those associated with self-generated movements. Surprisingly, the body transfer illusion had no influence on the ratings of tickliness, suggesting that highly surprising, and therefore hard to predict, experiences of body image and first-person perspective do not abolish the attenuation of tickle sensations. In addition, evidence was found that a version of the rubber hand illusion exists within the body transfer illusion. We situate our findings within the larger debate over sensory attenuation: (1) there is an attenuation of prediction errors that depends upon the context in which sensory input is predicted (i.e., efference copy), and (2) sensory attenuation is a necessary consequence of self-generated movement irrespective of context (i.e., active inference). The results support the notion of active inference.

Self compacting concrete from uncontrolled burning of rice husk and blended fine aggregate

This paper presents an experimental study on the development of normal strength Self compacting concrete (SCC) from uncontrolled burning of rice husk ash (RHA) as a partial replacement to cement and blended fine aggregate whilst maintaining satisfactory properties of SCC. Experiments on the fresh and hardened state properties have been carried out on RHA based SCC from uncontrolled burning. The dosages of RHA are limited to 0%, 20%, 30% and 40% by mass of the total cementitious material in the concrete. The experiments on fresh state properties investigate the filling ability, the passing ability and the segregation resistance of concrete. The experiments on hardened state properties investigate the compressive and the splitting tensile strengths. The water absorption level of the concrete with changing RHA levels has also been monitored. The experimental studies indicate that RHA based SCC developed from uncontrolled burning has a significant potential for use when normal strength is desired.

STUDIES ON EFFECT OF MINERAL ADMIXTURES ON DURABILITY PROPERTIES OF HIGH STRENGTH SELF COMPACTING CONCRETE

To build high rise building by reducing column size s and increasing available space, to built the supe r structure of long span bridges and to the durability of bridge decks a high streng th is needed. High strength concrete was used in So uth Wacker in Chicago of 80 Mpa, Baynunah Tower in Abu Dhabi of 80 MPa and Fran kfurt Trianon in Germany of 125 MPa. If high stren gth concrete is selfcompacting, the production of densely reinforced bu ilding element from high strength concrete with hig h homogeneity would be an easy work. In the present investigation a rational mix design is established and self compactability tmethods have been carried out from the view point of making it a standard con crete by using mineral admixtures like micro sili ca and fly ash for imparting High Strength Self Compacting Concrete. The flow proper ties of resulting concrete is characterized in the fresh state by methods used for Self compacting concrete, such as Slump-flow, V-fun nel and L- box tests respectively. Further the dura bility properties are examined for High Strength Self Compacting Concrete mix of gM100. The durability factors are also studied .From these studies we observe that 15% Micro silica and 25% Fly ash will give optimum strength for M100 grade at water /powd er ratio of 0.22. The effect of Na 2So 4 on these mixes is nil where as HCL and H 2So 4 had substantial impact.

Torsion Behavior of Steel Fibered High Strength Self Compacting Concrete Beams Reinforced by GFRB Bars

Torsion Behavior of Steel Fibered High Strength Self Compacting Concrete Beams Reinforced by GFRB Bars

Applications of the ANFIS and LR in the prediction of strain in tie section of concrete deep beams

Recent developments in Artificial Intelligence (AI) and computational intelligence have made it viable in the construction industry and structural analysis. This study usesthe Adaptive Network-based Fuzzy Inference System (ANFIS) as a modelling tool to predict the strain in tie section for High Strength Self Compacting Concrete (HSSCC) deep beams. 3773 experimental data were collected. The input data andits corresponding strains in tie section as output data were recorded at all loading stages. Results from ANFIS are compared with the classical linear regression (LR). The comparison shows that the ANFIS's results are highly accurate, precise and satisfactory.