Uporaba ultrazvočne metode za analizo vezanja in strjevanja betona

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Language:	Slovenian
Year of publishing:	2009
Source:	Ljubljana
Typology:	2.08 - Doctoral Dissertation
Organization:	UL FGG - Faculty of Civil and Geodetic Engineering
Publisher:	[G. Trtnik]
UDC:	004:519.22:620.179.16:691.32(043.3)
COBISS:	4553825
Views:	2200
Downloads:	758
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Secondary language:	English
Secondary title:	ǂThe ǂuse of ultrasonic method to monitor the setting and hardening process of concrete
Secondary abstract:	The objective of this work is to show the possibility of using an ultrasonic wave transmission method to monitor the setting and hardening process of cement based materials. Therefore, a comprehensive experimental work was performed. The ability of using ultrasonic wave transmission (USWT) and ultrasonic wave reflection (USWR) method to monitor the hydration process and to estimate the initial and final setting times of different cement based materials is studied in detail. The correlation between USWT and USWR methods in their ability to monitor the setting process of cement based materials is also studied. The influence of different concrete and environmetal parameters on the relationship between ultrasonic pulse velocity of longitudinal waves and concrete compressive strength is analysed. Based on the experimental results, a numerical model to predict the velocity-strength relationship is established within the Matlab programming environment. The multi-layer feed-forward neural network was used for this purpose. The idea of modeling adiabatic temperature rise during concrete hydration with the use of artificial neural networks is also introduced and numerical program is proposed, which can be used to predict the adiabatic hydration curve of an arbitrary concrete mixture. This model is implemented into the numerical procedure for calculation of temperature profile of early age mass concrete structure. Therefore, the main scientific contributions, presented in this dissertation, are: • to develop an experimental set-up to monitor the hydration process and formation of structure of different cement based materials as well as to estimate the initial and final setting times of these materials, • to analyse the correlation between the ultrasonic wave transmission and ultrasonic wave reflection method in their ability to monitor the setting process of cement based materials, • to analyse the influence of different concrete and environmental parameters on the relationship between the velocity of ultrasonic longitudinal waves and concrete compressive strength as well as to develop a suitable numerical model to predict the velocity-strength relationship of concrete mixture, • to analyse the influence of different concrete parameters on the development of adiabatic hydration curve as well as to develop a suitable numerical program to predict the adiabatic temperature rise of an arbitrary concrete mixture, • to develop a new numerical procedure for prediction of temperature profile of early age mass concrete structures, into which the proposed numerical program to predict the adiabatic hydration curves will be suitable included, • to perform the statistical analysis of the proposed methods and numerical programs.
Secondary keywords:	cement based materials;hydration;formation of structure;ultrasonic measurements;setting;compressive strength;adiabatic hydration curves;artificial neural networks;
URN:	URN:NBN:SI
File type:	application/pdf
Type (COBISS):	Dissertation
Thesis comment:	Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo
Pages:	XXVI, 152 str.
Keywords (UDC):	science and knowledge;organization;computer science;information;documentation;librarianship;institutions;publications;znanost in znanje;organizacije;informacije;dokumentacija;bibliotekarstvo;institucije;publikacije;prolegomena;fundamentals of knowledge and culture;propaedeutics;prolegomena;splošne osnove znanosti in kulture;computer science and technology;computing;data processing;računalniška znanost in tehnologija;računalništvo;obdelava podatkov;mathematics;natural sciences;naravoslovne vede;matematika;mathematics;matematika;probability;mathematical statistics;verjetnost;matematična statistika;applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;engineering;technology in general;inženirstvo;tehnologija na splošno;materials testing;commercial materials;power stations;economics of energy;preiskava materiala;blagoznanstvo;energetske centrale;energetika;applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;building (construction) trade;building materials;building practice and procedure;gradbeništvo;gradbeni materiali;gradbene obrti in dela;building materials;building components;gradiva;gradbeni [konstrukcijski] deli;
ID:	25417