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at the bottom flange and six on the web. Eight gages were installed at the approximate locations of the maximum positive and maximum negative moments. At each location four gages were installed; one at the top flange, one at the bottom flange and two equally spaced on the web. Finally, four gages were installed on two cross-bracing diaphragms between girders 5 and 6 one at about mid-span and the other over the support. The gages at each cross-bracing were located one on a chord member and the other on a diagonal. The weldable strain gages used are constantan alloy gages with backing and encapsulation of polyimide film. The gages are bonded to stainless steel carriers, 0.005 in. thick, and have exposed copper coated integral solder tabs to which wire cables were soldered directly. The cables were connected to three switch and balance units (10 channels each unit) thus providing a method of sequentially reading the strain gage information on a single strain indicator. As mentioned earlier the bridge was tested during construction; hence strain measurements were taken due to the weight of the wet concrete before and after three placements. After the deck slab has reached its design strength, and before placing the bituminous wearing surface, strain measurements were taken due to truck loads positioned at sixteen different positions on the bridge deck. Eight 3-axel trucks weighting about 60 kips each were used. The overall length of each truck is 24'-8" and the overall width is 8' 6". The aforementioned sixteen positions of the trucks consist of the following, In twelve positions the trucks were forming a line about 200 ft long at mid-span A between pier 3 and pier A,
DOI link for at the bottom flange and six on the web. Eight gages were installed at the approximate locations of the maximum positive and maximum negative moments. At each location four gages were installed; one at the top flange, one at the bottom flange and two equally spaced on the web. Finally, four gages were installed on two cross-bracing diaphragms between girders 5 and 6 one at about mid-span and the other over the support. The gages at each cross-bracing were located one on a chord member and the other on a diagonal. The weldable strain gages used are constantan alloy gages with backing and encapsulation of polyimide film. The gages are bonded to stainless steel carriers, 0.005 in. thick, and have exposed copper coated integral solder tabs to which wire cables were soldered directly. The cables were connected to three switch and balance units (10 channels each unit) thus providing a method of sequentially reading the strain gage information on a single strain indicator. As mentioned earlier the bridge was tested during construction; hence strain measurements were taken due to the weight of the wet concrete before and after three placements. After the deck slab has reached its design strength, and before placing the bituminous wearing surface, strain measurements were taken due to truck loads positioned at sixteen different positions on the bridge deck. Eight 3-axel trucks weighting about 60 kips each were used. The overall length of each truck is 24'-8" and the overall width is 8' 6". The aforementioned sixteen positions of the trucks consist of the following, In twelve positions the trucks were forming a line about 200 ft long at mid-span A between pier 3 and pier A,
at the bottom flange and six on the web. Eight gages were installed at the approximate locations of the maximum positive and maximum negative moments. At each location four gages were installed; one at the top flange, one at the bottom flange and two equally spaced on the web. Finally, four gages were installed on two cross-bracing diaphragms between girders 5 and 6 one at about mid-span and the other over the support. The gages at each cross-bracing were located one on a chord member and the other on a diagonal. The weldable strain gages used are constantan alloy gages with backing and encapsulation of polyimide film. The gages are bonded to stainless steel carriers, 0.005 in. thick, and have exposed copper coated integral solder tabs to which wire cables were soldered directly. The cables were connected to three switch and balance units (10 channels each unit) thus providing a method of sequentially reading the strain gage information on a single strain indicator. As mentioned earlier the bridge was tested during construction; hence strain measurements were taken due to the weight of the wet concrete before and after three placements. After the deck slab has reached its design strength, and before placing the bituminous wearing surface, strain measurements were taken due to truck loads positioned at sixteen different positions on the bridge deck. Eight 3-axel trucks weighting about 60 kips each were used. The overall length of each truck is 24'-8" and the overall width is 8' 6". The aforementioned sixteen positions of the trucks consist of the following, In twelve positions the trucks were forming a line about 200 ft long at mid-span A between pier 3 and pier A,
ABSTRACT