Reduction in critical design section for moment due to opening, can be overcome providing more closely on each side of the opening to maintain the necessary As. This is possible only when opening is possible to locate where moment is well below the compression capacity of the slab, thereby leaving the arrangement of reinforcement as the only problem. Of course, shear strength must be maintained, but this is rarely a problem except near the columns in flat slab type, as noted previously.
The arrangement of bars around any but minor opening can constitute a real problem. Bars running perpendicular to the face of an opening are not fully effective when simply cut0off at the opening.
This is acceptable if there is a beam at the opening to act as reaction for the slab. If there is no beam it is better to fan the bars out or splay them to go around the opening. If fanning or splaying leaves too wide an area without steel, extra bars can be placed parallel to the side of the opening, as indicated.
Code Requirement
13.5.2.1 In case of opening in intersecting middle strips, total amount of reinforcement required for the panel without opening is maintained.
13.5.2.2 In case of opening in intersecting column strips, an amount of reinforcement equivalent to that interrupted by an opening shall be added on the sides of the opening.
13.5.2.3
In case of opening common to one column strip and one middle strip not
more than ¼ the reinforcement in either strip shall be interrupted by
openings. An amount of reinforcement equivalent to that interrupted by
an opening shall be added on the sides of the opening.
Dear Sirs,
ReplyDeleteWe are KALMATRON® a SUPER CONCRETE ADDITIVE that we believe has no equal in the United States or world-wide.
We’re representatives of Kalmatron Corporation manufacturer of Concrete Class Upgrading Admixtures, Remedial Coats, and Concrete Regenerative Sprays.
"SEISMIC STAR" RFPatent#2006553, January 30,1994
"Seismic Star destroys the soil around its walls and your property stays on and unharmed."
"SEISMIC STAR" IS AN UNDERGROUND WALL BUILT AROUND THE HOUSE IS DESIGNED FOR DISSIPATION OF SHEAR RUPTURE BETWEEN SOIL AND THE WALLS OF "SEISMIC STAR" WITH REDUCTION OF IMPULSE SURPLUS PRESSURE BEGINNING FROM 40%.
This not a well-known self-sacrificial underground screen. A seismic shock destroys the soil around the SEISMIC STAR's walls only. Our company provides design of Seismic Star by unique software with blue prints and written warranty. We provide supervision on construction site by licensed contractor.
The Seismic Star' theory and its effectiveness are shown in “SEISMIC STAR BROCHURE" where it is proven that shape of the underground Seismic Star depends on the type of soil and level of quake attenuation required by the customer, which will be analyzed by uniqe software for every project.
http://www.seismicstar.com/SSBrochure.html
PROTECTION FROM POST-EARTHQUAKE EMISSION OF RADIATION
The Nuclear Power Stations and Nuclear Waste facilities causes the most dangerous post earthquake side effect. That’is why it is a necessity to require protection of your business building and house by radiation shielding stucco or venires of the roofs and walls.
We produce KALMATRON® KF-aby as a powder, which mixed with water applicable onto any surface by the stucco, shotctrete, or pre-caste venires technologies.
Vital distinction of KALMATRON® KF-aby from any other Radiation Shielding Materials is that protected structures do not become the secondary source of radiation.Our company provides supply of KALMATRON® KF-aby to the contractor's company familiar with conventional stucco and venire placing jobs where thickness of application specified radiation contamination including primordial one.
www.seismicstar.com
Regards,
Mr. Dilip Shah
NRD Industries
USA
E-mail : nrdindustries@gmail.com, KalmatronWorld@aol.com
Dr. Alex Rusinoff
Skype ID: dilipshah26
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