ELAZIG GUNISIGI NEWSPAPER - August 2010
DEFICIENCIES IN INSPECTIONS
Summer season, for us, is also the construction season. It is a period when the construction season is at its peak, and activities are at their highest level. The large number of construction projects makes inspections more challenging. While efforts are made to complete projects on time, certain parameters, which may seem like details but are crucial, can sometimes be overlooked. I believe it is necessary to review these overlooked deficiencies.
Building inspections fall under the authority of many institutions, and many organizations themselves conduct inspections of the constructions they commission. Our goal is not to point out the flaws, but to uncover the things that have been missed. In doing so, we aim to contribute further to building inspections.
Both globally and in our country, the latest earthquake regulations focus on the concept of ductile structures. The necessity for buildings to be designed with high energy absorption capacity to withstand earthquakes is the common result of scientific studies and experience. One of the key requirements for obtaining a ductile structure is the use of ductile reinforcement – essentially the steel reinforcements commonly used in construction. If the steel reinforcements used in construction are not compliant with standards, even if the quantity of reinforcements in the reinforced concrete load-bearing elements (such as shear walls, columns, beams, etc.) is sufficient, the performance of the building under earthquake forces will not meet expectations. Unfortunately, non-standard reinforcements are occasionally encountered in the construction market. Testing is a must to identify these non-compliant reinforcements. These cost-effective and practical tests help identify the suitability of the steel reinforcement, and such testing is carried out by many institutions. Whether the construction is in the public or private sector, continuous reinforcement inspections must be carried out by inspection mechanisms.
Concrete is an indispensable material in the construction sector. It has been used as a building material for over 120 years globally. Therefore, the basic principles regarding concrete have been well-established for many years. For concrete to have high strength, the quality of the materials used in its production must also be high, meaning they must comply with standards. Let us assume that concrete is prepared with materials that comply with standards, and following the appropriate rules. The identification of this compliance ensures high concrete strength. To determine concrete strength, samples are taken using standard molds. One of the most significant deficiencies in practice is the failure to take samples according to the established rules. If the samples are not taken in compliance with standards, the concrete strength value will not reflect the true value — whether too low or too high. The personnel conducting this task must be trained, informed, and even inspected. People who are not qualified or trained in the proper procedures should not take concrete samples.
Concrete samples must be properly stored by the inspection or supervision personnel. Only then will the inspection objective be achieved. Additionally, the appropriate number of samples as outlined by the standards must be collected. In practice, regardless of the size of the construction, typically only three samples are taken. However, relevant standards emphasize that as the amount of concrete increases, the number of samples should also increase.
Once the concrete is poured and has set for a certain amount of time, the molds are removed in sequence. Visually, irregularities in the cover thickness, significant surface defects, and voids in important areas of the reinforced concrete load-bearing elements provide critical information about the concrete and the pouring process. Such defects indicate that proper care was not taken in the concrete process. Inspectors and supervisors should pay attention to these appearances and determine the required level of caution for subsequent stages of construction.
Let us not forget, buildings behave under earthquake forces based on construction criteria, not project criteria.