ACI 207.3R-18 Report on Practices for Evaluation of Concrete in Existing Massive Structures for Service Conditions

ACI 207.3R-18 Report on Practices for Evaluation of Concrete in Existing Massive Structures for Service Conditions. 3.6.2 Routine inspections—A baseline inspection is generally performed shortly after the structure is put into service. Routine inspections by various organizations are generally made at a frequency of 6 months to 2 years after the baseline inspection. Additionally, inspections should be performed after signifcant earthquakes or foods. Inspections commonly consist of a visual examination of the condition of the exposed and accessible concrete in various components of a structure or project. Submerged structures or portions thereof may be visually examined by a diver or by a remotely- operated vehicle with an on-board video camera, or they may require dewatering. In some cases, visual examination may be supplemented by nondestructive tests, as described in Chapter 4, to indicate certain properties and conditions of the in-place concrete, such as compressive strength, modulus of elasticity, or the presence of voids and cracking. Data from instrumentation embedded in the concrete may also be available. A comparison of the concrete properties, conditions, and instrumentation at each inspection interval is a useful analysis tool and may reveal abnormal changes. Immediately after placing the structure into service, baseline inspections are typically performed so that performance can be assessed and, if necessary, modifcations can be made to design and operating practices. Inspections made thereafter should be directed at identifying any changes in condition of the concrete or concrete properties that may afect the integrity of the structure and its future serviceability. Inspections may be performed by trained technicians or qualifed engineers, depending on the program established. Reports describing the fndings of each routine inspection generally note any changed conditions, contain photographs of the conditions, and recommend corrective action. A condition survey includes a visual examination of exposed concrete to identify and defne areas of distress and examination of interior concrete. ACI 201.1R provides descriptions of distress and the methodology for producing visual inspection reports. ACI 201.1R should be reviewed prior to conducting a visual inspection. ASTM C823/C823M contains additional information useful in conducting a condition survey. The inspection should include a checklist of items of concern identifed in previous inspections and additional items based on the inspector’s experience and advancements in evaluation techniques. Perhaps the most important aspect related to the preparation for visual inspection is the review of available literature related to the structure or structural element. This should include original...