CONCRETE SLABS AND USE OF ADMIXTURES TO IMPROVE THE QUALITY OF CONCRETE - ITALY

THE THICKNESS OF CONCRETE SURFACINGS IS VARIABLE IN ITALY, VARYING FROM 15 TO 22 CM. REINFORCEMENT STUDIES ARE BEING CONDUCTED TO INCREASE THE RESISTANCE OF CONCRETE IN BENDING AND IN TENSION. LABORATORY TESTS ARE USED IN RESEARCHING THE EFFECT OF THE ADDITION OF THIN STEEL PIANO WIRES. EXPERIMENTAL PAVEMENT SECTIONS HAVE BEEN CONSTRUCTED WITH REINFORCEMENT CONSISTING OF METALLIC MESH. THE FUNCTION OF THE MESH IS TO PREVENT THE ENLARGEMENT OF CRACKS WHICH COULD BE FORMED AT THE SURFACE. TRANSVERSE JOINTS WERE CONSTRUCTED BY INSERTING A THIN PLANK OF TIMBER INTO THE CONCRETE. AFTER THE PASSAGE OF THE FINISHER THE UPPER LAYER OF THE CONCRETE IS CUT AND THE PLANK IS REMOVED. CONCRETE SLABS AFFECTED BY THERMAL ATMOSPHERIC VARIATIONS ARE SUBJECTED TO EXPANSIONS AND CONTRACTIONS. DISPLACEMENT OF THE ARRISES RESULTS FROM THOSE WHICH ARE NOT CONCORDANT. THE MATERIAL FOR FILLING THE JOINTS MUST BE WATERTIGHT TO PREVENT THE INFILTRATION OF WATER. MASTICS FROM TAR PITCH AND A CERTAIN QUANTITY OF ASBESTOS FIBRE ARE USED ON AIRPORT RUNWAYS AND ARE RESISTANT TO THE ACTION OF FUELS. SYSTEMATIC STUDIES OF THE VARIATION OF TEMPERATURE WITHIN THE CONCRETE SLABS WERE CONDUCTED WITH THERMAL ELECTRIC PROBES. GRAPHS SHOW THESE VARIATIONS AND THE PROGRESSIVENESS OF THE INCREASE OF TEMPERATURE IN PROPORTION TO THE REDUCTION IN THICKNESS OF THE SLAB, AS WELL AS THE INFLUENCE OF THE SURFACE. THE ADDITION OF SYNOPAL TO BITUMINIZED HIGHWAYS IS RECOMMENDED FOR BETTER VISIBILITY. EXPERIMENTAL WORK IS CONDUCTED ON PRESTRESSED SLABS TO ELIMINATE TRANSVERSE JOINTS. THE USE OF ENTRAINMENT AGENTS TO INCREASE THE RESISTANCE OF CONCRETE TO THE ACTION OF FREEZINF AND THAWING IS DISCUSSED. ADDITIVES WHICH ACT AS PLASTICIZERS THEREBY INCREASING MECHANICAL STRENGTH OR PREVENTING ITS REDUCTION AND SET RETARDERS ARE ANALYZED.

• Supplemental Notes:
  • No Iv-7, pp 3-12, 5 FIG
• Authors:
  • Ariano, R
• Publication Date: 1967

Media Info

• Serial:
  • Perm Intl Assoc Road Congresses Proc
  • Publisher: Xiiith Congress, Tokyo

Subject/Index Terms

• TRT Terms: Additives; Air entraining agents; Asbestos; Bending; Climate; Concrete; Construction management; Contraction; Expansion; Freeze thaw durability; Joint fillers; Laboratory tests; Mastic asphalt; Material reinforcement; Plasticizers; Prestressed concrete; Retarders (Concrete); Slabs; Steel wire; Tar; Temperature gradients; Tension; Thickness; Transverse joints; Visibility; Wire mesh
• Old TRIS Terms: Mastics; Retarders; Thickness design
• Subject Areas: Construction; Highways; Materials; Pavements;

Filing Info

• Accession Number: 00205544
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 3 1994 12:00AM