6C(1) Resolution No. 2732 - Laserfiche WebLink

Home Browse Search

Condition Assessment & Preventive Maintenance Program ~~ St. JosephlWayne Street Parking Garage City of South Bend June 29, 2010 Page 3 To aid in our visual observation for the discovery of deiaminated concrete, survey personnel will conduct a limited mechanical sounding evaluation (chain drag) on the top surface of the floor slabs, in order to record locations of spalled and/or delaminated concrete. A similar limited sounding evaluation will be performed at selected areas of the floor slab soffits, as well as columns, beams, and foundation walls, etc. 2. Waterproofing materials, such as: waterproofmg membranes and joint sealants. Special attention will be focused on moisture leakage through sealed cracks, if applicable. Task I-3 Conduct a concrete testing program during the on-site observation survey (Task I-2) of the parking garage. A testing program will be established in accordance with ASTM C823 recommendations as well as our experience with factors that affect the durability and life cycle of parking garage materials. A number of test methods are available to determine different properties of concrete, whether original construction or materials used for previous repairs. Concrete testing is intended to assist FUJAWA and DESMAN personnel in determining appropriate repairs and disposition of the existing surface treatment in order to most effectively extend the useful life of the parking structure. Methods may include tests such as: • Petrographic Examination (ASTM C856) to determine general properties of the original concrete and concrete materials used for subsequent repairs. • Acid Soluble Chloride Ion Content Analysis (ASTM C-1152) of concrete powder derived from powder samples taken directly from the slabs or concrete cores to determine current chloride levels. This enables us to understand the current as well as base (prior to exposure to the elements) chloride levels in order to qualify both current and future levels of corrosion of underlying reinforcing metals. • Pachometer (R Meter) (ACI 228) field testing to determine depth and location of embedded reinforcing steel and thickness of concrete cover. • Compressive Strength Analysis (ASTM C42-9Q) to determine concrete strength. • Half-Cell Potential Field Testing (ASTM C87b) to determine the corrosion potential of reinforcing steel within the concrete. These measurements indicate the potential for corrosion, but do not provide data on the rate of .corrosion. Linear polarization measurements are needed to establish actual rates of corrosion. • Water Absorption and Repellency (ASTM D-6489-99) to determine presence and depth of penetration of clear penetrating concrete sealers to the structural floor slabs as well as effectiveness and time frame for re-application of the clear sealers. This test entails splitting concrete core samples in half and dye checking the surface for depth of penetration of the sealer. We propose the following concrete testing program for the parking garage: TEST NO. Acid Soluble Chloride-Ion Content Analysis (ASTMCI152) from S locations 10 each Base Chloride-Ion Content Analysis from 2 locations 2 each For chloride-ion content analysis, two concrete powder samples will be obtained for laboratory analysis via drilled holes in the concrete slab; one sample from a depth of 0 to 1"