EXPERIMENTAL STUDY OF DOWELLED TRANSVERSE JOINTS WITH DIFFERENT CONFIGURATIONS IN RESPECT OF THE TRANSMISSION OF TRANSVERSE FORCES AND THE ANTI-SLIPPING PROPERTIES OF THE DOWELS

EXPERIMENTELLE UNTERSUCHUNG VON UNTERSCHIEDLICH AUSGEBILDETEN VERDUEBELTEN QUERFUGEN HINSICHTLICH DER QUERKRAFTUEBERTRAGUNG UND DES GLEITWIDERSTANDES DER DUEBEL

FIRST EXPERIMENTS WITH DOWELS AT A TEMPERATURE OF 20 DEGREES CENTIGRADE HAVE SHOWN THAT AT THIS TEMPERATURE DOWELLING OF CONCRETE SLABS GIVES ADEQUATE PROTECTION AGAINST OVERSTRESSING. AT HIGHER OR LOWER TEMPERATURES DIFFERENT BEHAVIOUR IS EXPECTED BECAUSE OF THE SOFTENING OR EMBRITTLEMENT OF THE BITUMINOUS COATING. LOADING TESTS WILL THEREFORE BE CARRIED OUT IN A TEMPERATURE RANGE FROM 10 DEGREES TO PLUS 40 DEGREES CENTIGRADE, WITH DIFFERENT DOWEL CROSS SECTIONS AND ALSO FOR COMPARISON WITH A PLASTIC PAINT. A UNIVERSAL VIBRATORY TEST MACHINE IS AVAILABLE FOR THE EXPERIMENTS, WHICH WILL ALLOW FORCE DISTRIBUTION IN TWO DIRECTIONS. THE TEST SPECIMENS ARE 1.5 WIDE AND 1.5 M LONG. BEFORE THE DURABILITY TESTS ARE STARTED, THE JOINTS IN THE SPECIMENS ARE OPENED FIVE TIMES AND THE RESISTANCE TO STRETCHING IS MEASURED, THEN, WITH THE JOINTS OPENED TO 0.5 MM, TWO MILLION ALTERNATIONS OF LOAD ARE APPLIED, WITH THE SPECIMEN LYING ON A RUBBER UNDERLAY WHICH REPRESENTS THE SUBGRADE OF THE CONCRETE PAVING. IN ALL, IN ADDITION TO PRELIMINARY TESTS TO DETERMINE THE MOST SUITABLE PLASTIC PAINT, SEVEN TEST SPECIMENS WITH DIFFERENT DOWEL DIAMETERS AND SPACINGS WILL BE SUBJECTED TO THE DOWEL TESTS, IN WHICH THE TEMPERATURE WILL BE VARIED BETWEEN MINUS 10 DEGREES CENTIGRADE AND PLUS 40 DEGREES CENTIGRADE AT EVERY 100000 LOAD ALTERNATIONS.