ΜΕΛΕΤΗ ΤΩΝ ΦΥΣΙΚΟΧΗΜΙΚΩΝ ΔΙΕΡΓΑΣΙΩΝ ΕΝΑΝΘΡΑΚΩΣΗΣ ΤΟΥ ΣΚΛΗΡΥΜΕΝΟΥ ΤΣΙΜΕΝΤΟΠΟΛΤΟΥ ΚΑΙ ΤΩΝ ΕΠΙΠΤΩΣΕΩΝ ΣΤΗΝ ΑΝΘΕΚΤΙΚΟΤΗΤΑ ΣΕ ΔΙΑΡΚΕΙΑ ΤΟΥ ΟΠΛΙΣΜΕΝΟΥ ΣΚΥΡΟΔΕΜΑΤΟΣ

STEEL BARS IN REINFORCED CONCRETE ARE PROTECTED FROM CORROSION BY THE HIGH PH ENVIRONMENT OF THE SURRONDING CONCRETE. THIS ALKALINE ENVIRONMENT IS DESTROYED BY THE GRADUAL DIFFUSION OF ATMOSPHERIC CO2 INTO THE CONCRETE PORES, AND ITS REACTION WITH THE CA(OH)2 OF THE CONCRETE MASS. WHEN THIS PROCESS, CALLED CARBONATION OF CONCRETE, REACHES THE REINFORCING BARS, CORROSION OF THE LATTER MAY COMMENCE. IN THIS WORK THE PHYSICOCHEMICAL PROCESSES IN THIS PHENOMENON ARE PRESENTED AND MODELED MATHEMATICALLY, USING FIRST PRINCIPLES AND METHODS OF REACTION ENGINEERING. THE MATHEMATICAL MODEL IS FAIRLY COMPLEX, BUT FOR THE RANGE OF PARAMETER VALUES FOUND IN PRACTICE CERTAIN SIMPLYFYING ASSUMPTIONS CAN BE MADE, WHICH LEAD TO THE FORMATION OF A "CARBONATION FRONT" AND TO A SIMPLE ANALYTICAL EXPRESSION FOR THE EVOLUTION IN TIME OF THIS FRONT, IN TERMS OF THE COMPOSITION OF CEMENT, WATER/CEMENT AND AGGREGATE/CEMENT RATIOS OF CONCRETE AND OF THE ENVIRONMENTAL CONDITIONS, I.E., ATMOSPHERIC CONCENTRATION OF CO2, RELATIVE HUMIDITY AND TEMPERATURE. THIS SIMPLE EXPRESSION IS IN VERY GOOD AGREEMENT WITH EXPERIMENTAL RESULTS OF PREVIOUS WORKERS AND ALSO WITH RESULTS OBTAINED IN THIS WORK USING AN ACCELARATED CARBONATION APPARATUS. THE EFFECT OF SOME PARAMETERS ON THE VELOCITY OF PROPAGATION OF THE CARBONATION FRONT IS ALSO, DISCUSSED.

Grantor dc:publisher

University of Patras

Year dc:date

1990

Author dc:creator

• Παπαδάκης, Ευάγγελος

• Ανθεκτικότητα σε διάρκεια
• Διάβρωση οπλισμού
• Διάχυση
• Ενανθράκωση σκυροδέματος
• ΙΔΙΟΤΗΤΕΣ ΣΚΥΡΟΔΕΜΑΤΟΣ
• Σκυρόδεμα
• Τσιμέντο
• ΧΡΟΝΟΣ ΧΡΗΣΙΜΗΣ ΖΩΗΣ
• Cement
• Concrete
• Concrete carbonation
• Concrete durability
• CONCRETE PROPERTIES
• Diffusivity
• Reinforcement corrosion
• SERVICE LIFE TIME
• Επιστήμες Μηχανικού και Τεχνολογία
• Επιστήμη Χημικού Μηχανικού
• Engineering and Technology
• Chemical Engineering

Language dc:language

gre

Identifier

10.12681/eadd/1496

OAI identifier oai:identifier

oai:10442/1496