scholarly journals Compressive Creep and Shrinkage of High-Strength Concrete Based on Limestone Coarse Aggregate Applied to High-Rise Buildings

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5026
Author(s):  
Euichul Hwang ◽  
Gyuyong Kim ◽  
Kyungmo Koo ◽  
Hyungjae Moon ◽  
Gyeongcheol Choe ◽  
...  
Keyword(s):  
High Strength Concrete ◽  
Large Scale ◽  
Prediction Models ◽  
Coarse Aggregate ◽  
High Strength ◽  
Actual Structure ◽  
Compressive Creep ◽  
Curing Conditions ◽  
Strength Concrete ◽  
High Rise

Concrete undergoes shrinkage regardless of the influence of external forces. The deformation of concrete is crucial for the structural stability of high-rise and large-scale buildings. In this study, the shrinkage and compressive creep of 70–90 MPa high-strength concrete used in high-rise buildings were evaluated based on the curing conditions (sealed/unsealed), and the existing prediction models were examined. It was observed that the curing condition does not significantly affect the mechanical properties of high-strength concrete, but the use of limestone coarse aggregate increases the elastic modulus when compared to granite coarse aggregate. The autogenous shrinkage of high-strength concrete is greater than that of normal-strength concrete owing to self-desiccation, resulting in a large variation from the value predicted by the model. The drying shrinkage was observed to be similar to that predicted by the model. Compressive creep was affected by the curing conditions, compressive strength, loading level, and loading age. The compressive creep of high-strength concrete varied significantly from the prediction results of ACI 209; ACI 209 was modified based on the measured values. The shrinkage and compressive creep characteristics of high-strength concrete must be reflected to predict the deformation of an actual structure exposed to various conditions.

Estimation of Compressive Strength of Recycled Aggregate High Strength Concrete Using Ultrasonic Pulse Velocity

2014 ◽  
Vol 605 ◽  
pp. 147-150
Author(s):  
Seong Uk Hong ◽  
Seung Hun Kim ◽  
Yong Taeg Lee
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Recycled Aggregate ◽  
Strength Concrete ◽  
Recycled Coarse Aggregate

This study used the ultrasonic pulse velocity method, one of the non-destructive test methods that does not damage the building for maintenance of to-be-constructed concrete structures using recycled aggregates in order to estimate the compressive strength of high strength concrete structure using recycled coarse aggregate and provide elementary resources for technological establishment of ultrasonic pulse velocity method. 200 test pieces of high strength concrete 40, 50MPa using recycled coarse aggregate were manufactured by replacement rates (0, 30, 50, 100%) and age (1, 7, 28, 180days), and air curing was executed to measure compressive strength and wave velocity. As the result of compressive strength measurement, the one with age of 180day and design strength of 40MPa was 43.69MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 42.82, 41.22, 37.35MPa, and 50MPa was 52.50MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 49.02, 46.66, 45.30MPa, and while it could be seen that the test piece substituted with recycled aggregate was found to have lower strength than the test piece with natural aggregate only, but it still reached the design strength to a degree. The correlation of compressive strength and ultrasonic pulse velocity was found and regression analysis was conducted. The estimation formula for compressive strength of high strength concrete using recycled coarse aggregate was found to be Fc=0.069Vp4.05, R2=0.66

Field study of residual forces developed in pre-stressed high-strength concrete (PHC) pipe piles

2016 ◽  
Vol 53 (4) ◽  
pp. 696-707 ◽  
Author(s):  
Hai-lei Kou ◽  
Jian Chu ◽  
Wei Guo ◽  
Ming-yi Zhang
Keyword(s):  
Static Loading ◽  
High Strength Concrete ◽  
Large Scale ◽  
Load Transfer ◽  
High Strength ◽  
Neutral Plane ◽  
Shaft Resistance ◽  
Strength Concrete ◽  
Loading Tests ◽  
Residual Force

A large-scale field testing program for the study of residual forces in pre-stressed high-strength concrete (PHC) pipe piles is presented in this paper. Five open-ended PHC pipe piles with 13 or 18 m in embedded length were installed and used for static loading tests at a building site in Hangzhou, China. All the piles were instrumented with fiber Bragg grating (FBG) strain gauges. The residual forces in these piles were recorded during and after installation. The measured load transfer data along a pile during the static loading tests are reported. The effect of the residual force on the interpretation of the load transfer behavior is discussed. The field data show that residual force along the installed pile increases approximately exponentially to the neutral plane and then reduces towards the toe. The residual force decreases with time to a stable value after pile jacking due to the secondary interaction between the pile and the disturbed soil around the pile and other factors. The large residual forces along the PHC pipe piles significantly affect the evaluation of the pile load distributions, and thus the shaft and toe resistances. The conventional bearing capacity theory tends to overestimate the shaft resistance at positions above the neutral plane and underestimate the shaft resistance at positions below the neutral plane, and the toe resistance for an open-ended PHC pipe piles founded in stratified soils.

The Possibility of Using Boiler Slag as Coarse Aggregate in High Strength Concrete

2017 ◽  
Vol 22 (5) ◽  
pp. 1816-1826 ◽  
Author(s):  
Piotr Smarzewski ◽  
Danuta Barnat-Hunek ◽  
Walery Jezierski
Keyword(s):  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Strength Concrete

scholarly journals Effect of Curing Temperature Histories on the Compressive Strength Development of High-Strength Concrete

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Keun-Hyeok Yang ◽  
Jae-Sung Mun ◽  
Myung-Sug Cho
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Relative Strength ◽  
Curing Temperature ◽  
Strength Development ◽  
Curing Conditions ◽  
Strength Concrete ◽  
Equivalent Age ◽  
Compressive Strength Development

This study examined the relative strength-maturity relationship of high-strength concrete (HSC) specifically developed for nuclear facility structures while considering the economic efficiency and durability of the concrete. Two types of mixture proportions with water-to-binder ratios of 0.4 and 0.28 were tested under different temperature histories including (1) isothermal curing conditions of 5°C, 20°C, and 40°C and (2) terraced temperature histories of 20°C for an initial age of individual 1, 3, or 7 days and a constant temperature of 5°C for the subsequent ages. On the basis of the test results, the traditional maturity function of an equivalent age was modified to consider the offset maturity and the insignificance of subsequent curing temperature after an age of 3 days on later strength of concrete. To determine the key parameters in the maturity function, the setting behavior, apparent activation energy, and rate constant of the prepared mixtures were also measured. This study reveals that the compressive strength development of HSC cured at the reference temperature for an early age of 3 days is insignificantly affected by the subsequent curing temperature histories. The proposed maturity approach with the modified equivalent age accurately predicts the strength development of HSC.

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