Prediction model for relative humidity of early-age internally cured concrete with pre-wetted lightweight aggregates

2017 ◽  
Vol 144 ◽  
pp. 717-727 ◽  
Author(s):  
Dejian Shen ◽  
Mingliang Wang ◽  
Ying Chen ◽  
Tao Wang ◽  
Jinyang Zhang
Keyword(s):  
Relative Humidity ◽  
Prediction Model ◽  
Early Age ◽  
Lightweight Aggregates

scholarly journals Instability indices and forecasting thunderstorms: the case of 30 April 2009

2012 ◽  
Vol 12 (2) ◽  
pp. 403-413 ◽  
Author(s):  
S. Tajbakhsh ◽  
P. Ghafarian ◽  
F. Sahraian
Keyword(s):  
Relative Humidity ◽  
Prediction Model ◽  
Numerical Weather Prediction ◽  
Vertical Velocity ◽  
Weather Prediction ◽  
Numerical Weather Prediction Model ◽  
Weather Station ◽  
Using Data ◽  
Instability Indices

Abstract. In this paper, one meteorological case study for two Iranian airports are presented. Attempts have been made to study the predefined threshold amounts of some instability indices such as vertical velocity and relative humidity. Two important output variables from a numerical weather prediction model have been used to survey thunderstorms. The climatological state of thunder days in Iran has been determined to aid in choosing the airports for the case studies. The synoptic pattern, atmospheric thermodynamics and output from a numerical weather prediction model have been studied to evaluate the occurrence of storms and to verify the threshold instability indices that are based on Gordon and Albert (2000) and Miller (1972). Using data from the Statistics and Data Center of the Iran Meteorological Organization, 195 synoptic stations were used to study the climatological pattern of thunderstorm days in Iran during a 15-yr period (1991–2005). Synoptic weather maps and thermodynamic diagrams have been drawn using data from synoptic stations and radiosonde data. A 15-km resolution version of the WRF numerical model has been implemented for the Middle East region with the assistance of global data from University Corporation for Atmospheric Research (UCAR). The Tabriz airport weather station has been selected for further study due to its high frequency of thunderstorms (more than 35 thunderstorm days per year) and the existence of an upper air station. Despite the fact that storms occur less often at the Tehran weather station, the station has been chosen as the second case study site due to its large amount of air traffic. Using these two case studies (Tehran at 00:00 UTC, 31 April 2009 and Tabriz at 12:00 UTC, 31 April 2009), the results of this research show that the threshold amounts of 30 °C for KI, −2 °C for LI and −3 °C for SI suggests the occurrence and non-occurrence of thunderstorms at the Tehran and Tabriz stations, respectively. The WRF model output of vertical velocity and relative humidity are the two most important indices for examining storm occurrence, and they have a numerical threshold of 1 m s−1 and 80%, respectively. These results are comparable to other studies that have examined thunderstorm occurrence.

Research on Self-Desiccation at early Age of High Performance Concrete with Polypropylene Fiber

2011 ◽  
Vol 374-377 ◽  
pp. 1827-1830
Author(s):  
Wei Wei Yu ◽  
Qing Xiong ◽  
Yun Yu ◽  
Hang Lin
Keyword(s):  
Relative Humidity ◽  
High Performance ◽  
High Performance Concrete ◽  
Polypropylene Fiber ◽  
The Self ◽  
Experimental Results ◽  
Early Age ◽  
Experimental Conditions ◽  
Internal Relative Humidity ◽  
The Impact

This paper focuses on the impact which polypropylene fiber (PF) has on the self-desiccation effect at early age of high performance concrete (HPC). The experimental results indicate that PF has little influence on the Internal Relative Humidity (IRH) caused by self-desiccation effect of concrete, but can reduce early aged self-desiccation shrinkage of concrete. With the PF dosage increasing, the values of early self-desiccation shrinkage of HPC decrease first and then increase. In the experimental conditions, the value of self-desiccation shrinkage of concrete with 0.6Kg/m3 PF is the lowest one.

scholarly journals Using the Maturity Method in Predicting the Compressive Strength of Vinyl Ester Polymer Concrete at an Early Age

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Nan Ji Jin ◽  
Kyu-Seok Yeon ◽  
Seung-Ho Min ◽  
Jaeheum Yeon
Keyword(s):  
Compressive Strength ◽  
Prediction Model ◽  
Vinyl Ester ◽  
Curing Temperature ◽  
Polymer Concrete ◽  
Early Age ◽  
Time Interval ◽  
Study Results ◽  
Maturity Method ◽  
Curing Age

The compressive strength of vinyl ester polymer concrete is predicted using the maturity method. The compressive strength rapidly increased until the curing age of 24 hrs and thereafter slowly increased until the curing age of 72 hrs. As the MMA content increased, the compressive strength decreased. Furthermore, as the curing temperature decreased, compressive strength decreased. For vinyl ester polymer concrete, datum temperature, ranging from −22.5 to −24.6°C, decreased as the MMA content increased. The maturity index equation for cement concrete cannot be applied to polymer concrete and the maturity of vinyl ester polymer concrete can only be estimated through control of the time interval Δt. Thus, this study introduced a suitable scaled-down factor (n) for the determination of polymer concrete’s maturity, and a factor of 0.3 was the most suitable. Also, the DR-HILL compressive strength prediction model was determined as applicable to vinyl ester polymer concrete among the dose-response models. For the parameters of the prediction model, applying the parameters by combining all data obtained from the three different amounts of MMA content was deemed acceptable. The study results could be useful for the quality control of vinyl ester polymer concrete and nondestructive prediction of early age strength.

scholarly journals Study and Application on Big Data Information Fusion System Based on IoT

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lina Zheng
Keyword(s):  
Big Data ◽  
Relative Humidity ◽  
Light Intensity ◽  
Prediction Model ◽  
Information Fusion ◽  
Co2 Concentration ◽  
Training Data ◽  
Fusion Technology ◽  
Climate Data ◽  
Zigbee Technology

In our study, we first illustrated information fusion technology and Internet of Things (IoT), and then we built farmland IoT information collection platform on the basis of ZigBee technology and agricultural sensors to collect climate data including air pressure, temperature, soil water content, light intensity, and relative humidity. Finally, prediction model was used to evaluate crop growth condition. Results show that temperature increases with time and reaches the maximum at 13:00 PM. But relative humidity decreases with time and reaches the maximum at 3:30 AM. Light intensity presents a straight trend with time and reaches the maximum at 13:30 PM. CO2 concentration presents a fluctuation trend with time and reaches high point at 7:00 AM. Prediction model presented a high accuracy outcome with 99% accuracy in training data and 100% in testing set. Therefore, we can conclude that big data fusion technology on the basis of IoT has a good future in many fields excepting agriculture crop, which is also an irreversible trend.

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