THE IMPACT RESISTANCE OF CONCRETE FOR DRIVEN PILES /IN GERMAN/

FOR THE PRESENT TESTS ON THE IMPACT RESISTANCE OF CONCRETE FOR DRIVEN PILES THE IMPACT TESTING APPARATUS STANDARDIZED IN DIN 52107 WAS RECONSTRUCTED SO THAT ITS REPEATED BLOWS OF A 50 KG DROP HAMMER CAN BE APPLIED TO A CONCRETE CYLINDER (D=15 CM, H=30 CM) FROM A UNIFORM, PRESCRIBED DROP HEIGHT (10 TO 150 CM). THE ELECTRONIC MEASURING DEVICE PERMITS THE RECORDING AND REGISTRATION OF THE NUMBER OF BLOWS, THE FORCE INTRODUCED, THE DISTORTION IN THE LONGITUDINAL AND CROSSWISE DIRECTION AND ALSO THE COURSE OF TIME OF ALL OPERATIONS. ON THE BASIS OF VARIOUS PRELIMINARY TESTS THE IMPACT RESISTANCE IN THESE TESTS WAS DETERMINED AS THE NUMBER OF BLOWS OF THE 50 KG HAMMER FROM A DROP HEIGHT OF 80 CM. THE TESTS CONFIRM THE EXPERIENCES GAINED IN PRACTICE THAT A HIGH CYLINDER COMPRESSIVE STRENGTH OF AT LEAST 450 KP/SQ. CM. (COMPRESSIVE STRENGTH OF THE 20 CM CUBE ABOUT 380 KP/SQ. CM) AND A HIGH CLEAVAGE TENSILE STRENGTH OF AT LEAST 35 KP/SQ. CM. ARE INDEED, PRIOR CONDITIONS FOR A HIGH IMPACT RESISTANCE, BUT NO ADEQUATE GUARANTEE OF THIS. ALSO NECESSARY ARE GOOD ADHESION BETWEEN THE CEMENT STONE AND AGGREGATE AND, WITH A HIGH INHERENT STRENGTH, THE MOST UNIFORM POSSIBLE DISTORTION BEHAVIOR FROM CEMENT STONE LAYER AND AGGREGATE. THIS IS ACHIEVED THROUGH DOUBLY CRUSHED AGGREGATES WITH HIGH STRENGTH BUT A COMPARATIVELY LOW MODULUS OF ELASTICITY AND LOW LATERAL STRAIN (QUARTZITE AND BLAST-FURNACE SLAG). ALSO FAVOURABLE ARE A MAXIMUM PARTICLE SIZE OF 15 MM, A SAND CONTENT 017 MM OF AT LEAST 60% AND, AFTER AN INITIAL 7 DAYS MOIST STORAGE, SEVERAL WEEKS OF DRY STORAGE. /RRL/A/

• Supplemental Notes:
  • Vol 18, No 4, PP 131-136, 10 FIG, 10 TAB, 7 PHOT, 34 REF
• Corporate Authors:

  BetonVerlag GmbH

  Duesseldorfer Strasse 8, Postfach 450
  4 Duesseldorf,   Germany 
• Authors:
  • Dahms, J
• Publication Date: 1968

Media Info

• Serial:
  • Beton
  • Publisher: BetonVerlag GmbH

Subject/Index Terms

• TRT Terms: Adhesion; Aggregates; Concrete; Driving; Shock resistance; Strength of materials; Support piles; Testing equipment
• Uncontrolled Terms: Impact strength; Particle size distribution
• Old TRIS Terms: Concrete piles
• Subject Areas: Construction; Geotechnology; Highways;

Filing Info

• Accession Number: 00214999
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS
• Created Date: Mar 20 1972 12:00AM