Heritage Concrete Structure - Literature review Example

HERITAGE CONCRETE By Student’s name Course code and name Professor’s name University name City, State Date of submission Literature Review The overwhelming usage of heritage concrete during the 20th century has brought a renewed interest in its study. Although its usage as a construction material dates back to the Roman Empire, growing attention has been diverted to innovative modern architects that are deemed to be of historical importance. This is because of the developments that occurred to this field of materials both technically and theoretically. It however has to be noted that concrete does not last forever due to natural forces of destruction that include weather and human activity thus it is important to study this topic as a fulfillment of the objectives highlighted in the research proposal (Valenca & Julio, 2010). A basic analysis of the structural strengths by Soudki (2011), indicate that the proportion of the constituents that make up concrete are responsible for concrete properties. The durability of concrete is drawn from the varying ratios from which the final material emanates. While water has been considered as the most affecting factor of concrete, it is also an underlying deterioration factor. Another long term factor that is contributory to the deterioration of concrete structures is the deleterious effect that is posed by corrosion attack on the reinforcement bars. These factors according to Hilsdorf and Kropp (2004), are combined to define concrete durability which is basically the ability to resist chemical attacks, weathering action and abrasion among other processes associated with deterioration. Weathering and carbonation have however been given a higher importance in this research owing to their wanton effects on heritage concrete. Concrete damage due to carbonation majorly affects steel reinforced concrete when carbon dioxide dissolves in water forming carbonic acid which in turn leads to large scale corrosion. Thin sections are more susceptible to collapsing or even destruction when protective coatings are not applied (Soudki, 2001). On the other side, weathering has also been discovered to cause massive destruction on heritage concrete if it goes unchecked. Most archeological sites have been found to result into ruins due to this uncontrolled activity. This process is affected by human and other natural phenomenon such as soil temperatures (uncontrollable), presence of soluble salts, dissolved carbon dioxide, vegetation cover, soil pH and concrete particle size (Kaplan, et al., 2013). Fast forward to the matter of contention which is with regard to heritage concrete deterioration, means of conservation have been formulated enthusiast within this field. English Heritage (2012) in their book “Practical Building Conservation: Concrete” detail on various methodologies of ensuring that concrete achieves full life cycle through methods such as patch and scale repair whenever faults are observed by those entrusted to the conservation mandates. Patching and or large scale repair works are advocated for by Matthews et al. (2012). This is meant to provide short term to long term solutions depending on the deterioration factors. It is also important to use surface coatings as a major approach for concrete conservation where carbonation is a major issue. Surface impregnation is also another conservation trend that has been hailed by (Raupach & Büttner, 2014; FIP Commission on Practical Construction, 1991) due to the moisture reducing factor that it instills to heritage concrete. Although this approach deters the natural look of concrete, it is worth practicing especially in the United Kingdom where moisture is a major deterioration factor. Other notable means of conservation include cathodic protection and erection of ventilated rains screens. Cathodic protection is advocated for during the initial stages of construction as they provide alternatives to patching and coating. It has often been illustrated in conference proceedings such as “Concrete solution 2014” on how anode protection through application of the cathodic reactions can aid in ensuring that strengthened or reinforced concrete is in a preserved condition. While preservation of heritage concrete is seen to pose as a major problem facing the concrete fraternity, it has also been noted that repair materials may also age in the process of preservation. This may lead to worse scenarios such as disfiguring of the heritage concrete of collapse of structures in cases where reinforcements have been applied. It has also been discovered that with variations in strengths due to technological innovation, materials chosen for the purpose of preservation may not match with those utilized for heritage concrete. For example, while pozzolanic cement may be advocated for inland heritage concrete, using it for offshore concrete may not be well adapted for this kind of use and may deteriorate or react with the initial materials utilized hence lead to further deterioration. It is therefore important to monitor constantly and also to utilize materials that are deemed to be in the same reactivity series as those initially used in coming up with the structure (Kormann, et al., 2003). In order to ensure the integrity of heritage concrete structures, there are various methods that have set in to assist in doing so. These are majorly classified into two broad groups namely non-destructive and destructive testing. For the purpose of this thesis, the nondestructive testing methodologies are given importance due to their ability to establish structural integrity without necessarily tampering with the historic outlook. For purposes of heritage concrete investigation, ultrasound and surface hardness through Schmidt tests are highly advocated for by (Fort, et al., 2013; Rainieri, et al., 2013) due to the granular nature of concrete. It is a known fact that for sure microcracks and flaws cause weakness due to enhanced water absorption. Thus these cracks are often investigated during the nondestructive exercise in order to attempt fix this problem. According to Moropoulou, et al. (2013), ultrasonic testing utilizes high frequency sound waves to establish irregularities in material homogeneity when the received signal is attenuated leading to loss of energy. This methodology is highly used in areas where flaws or discontinuities are highly suspected. Schmidt test on the other side is highly utilized in detecting surface hardness by investigating the tensile properties of concrete. Samples are analyzed to identify the weathering indices from time to time in order to establish the repair areas in accordance to comparative analysis results usually resulting from better areas of the heritage structure (Viles, et al., 2011). Other important methods of identifying deterioration in heritage concrete include X-ray fluorescence spectroscopy, checking for differences in physical deterioration by use of digital image processing or spectrophotometers and being on the lookout for carbonation by using Carbo Detect™ methodologies among others (Alani, et al., 2014). Digital image processing utilizes software capable of carrying out analysis of digital images while recognizing architectural patterns for purposes of classification. The principle that is exploited in this technology is based on macroscale applications which use reflected light to determine denudation levels based in a given base comparison. This method however requires revalidation through other methods such as microscopy and physical textural investigation (Moropoulou, et al., 2013). X-ray fluorescence spectroscopy is a very important comparative NDT methodology when it comes to establishing the chemical composition. High energy X-rays are bombarded on the sample and the fluorescent emission spectrum caused is collimated into a parallel beam which is then directed onto a detector. The wavelengths that are tapped in the long run are found to differ thus their densities are likened to those established in various elements that have been investigated before. The whole process is advantageous in that it is fast and the samples can be reused on returned back to their original position after the analysis exercise is completed (Bungey & Millard, 2010). The concerns raised about preservation of heritage concrete have led to development of advanced technology in order to constantly carry out monitoring. As such, various methodologies have been realized for this purposes with benefits being majorly emergency surveys and preventative maintenance. The restoration exercises require sustainable strategies such as ground-based radar interferometry (GBInSAR) and Terrestrial laser scanning (TLS) or a combination of both (Tapete, et al., 2013). Figure 1: Typical representation of the ground-based radar interferometry (GBInSAR) (Tapete, et al., 2013). The ground-based radar interferometry (GBInSAR) method basically deploys a non-invasive imaging technique which gives way for observation of superficial deformation through a calculated phase difference in collected data. Further, this method contains a ground installed platform which is equipped with two antennas i.e. one transmitter and one receiver. From the data obtained while antennas are sweeping through allocated surfaces, it is obvious that spatial images can be generated for advanced analysis (Atzeni, et al., 2014). Terrestrial laser scanning according to Temizer, et al., (2013) is a noninvasive technique which is used in areas that are inaccessible and can be used for hundreds of meters with a millimeter accuracy level. This technology has been used for architectural survey and can fit very well into heritage structures surveillance. It can be used for generation of 3D models which are handy in dimensional analysis of stability due to their high resolution characteristic. For purposes of deformation monitoring in heritage concrete, this method has however proven slow and at times ineffective due to cloud cover (for satellite enabled laser gadgets). References ACI Committee 546, 2001. Concrete Repair Guide. ACI 546R-96, pp. Pp. 1-41. Alani, A. M., Aboutalebi, M. & Kilic, G., 2014. Integrated health assessment strategy using NDT for reinforced concrete bridges. NDT&E International, Volume 61, pp. Pp 80-94. Anon., 2014. Conserving our Wartime Heritage: A Reinforced Concrete Air Raid Shelter in East. Journal of Architectural Conservation, 37(41), pp. Pp. 81-100. Atzeni, C., Barla, M., Pieraccini, M. & Antolini, F., 2014. Early warning monitoring of natural and engineered slopes with ground-based synthetic aperture radar. Rock mechanics and rock engineering, Volume 1, pp. Pp. 1-19. Behnia, A., Chai, H. K. & Shmiostani, T., 2014. Advanced structural health monitoring of concrete structures with the aid of acoustic emission. Construction and Building Materials, Volume 65, pp. Pp. 282-302. Brimblecombe, P., 2014. Refining climate change threats to heritage. Journal of the Institute of Conservation, 37(2), pp. Pp. 85-93. Bungey, J. H. & Millard, S. G., 2010. Testing of Concrete in Structures, Third Edition. New York: CRC Press. Carcangiu, G. et al., 2014. Microclimatic monitoring of a semi-confined archaeological site affected by salt crystallisation. Journal of Cultural Heritage, Volume xxx, pp. Pp. 1-6. Coombes, M. A., Feal-Pérez, A., Naylor, L. A. & Wilhelm, K., 2013. A non-destructive tool for detecting changes in the hardness of engineering materials: Application of the Equotip durometer in the coastal zone. Engineering Geology, Volume 167, pp. Pp. 14-19. English Heritage, 2012. Practical Building Conservation: Concrete. Holborn, London: Ashgate Publishing, Ltd.. FIP Commission on Practical Construction, 1991. Repair and Strengthening of Concrete Structures. Kent: Thomas Telford. Fort, R., de Buergo, M. A. & Perez-Monserrat, E. M., 2013. Non-destructive testing for the assessment of granite decay in heritage structures compared to quarry stone. International Journal of Rock Mechanics & Mining Sciences, Volume 61, pp. Pp. 296-305. Grantham, M., Basheer, P. A. M., Magee, B. & Soutsos, M., 2014. Concrete Solutions 2014. Belfast, CRC Press. Hellebois, A. et al., 2013. 100-year-old Hennebique concrete, from composition to performance. Construction and Building Materials, Volume 44, pp. Pp. 149-160. Hilsdorf, H. & Kropp, J., 2004. Performance Criteria for Concrete Durability. New York: CRC Press. Kanli, A. I. et al., 2015. GPR survey for reinforcement of historical heritage construction at fire tower of Sopron. Journal of Applied Geophysics, Volume 112, pp. Pp. 79-90. Kaplan, C. D., Murtezaoglu˘ , F., Ipekoglu, B. & Boke, H., 2013. Weathering of andesite monuments in archaeological sites. Journal of Cultural Heritage, Volume 14S, pp. Pp. e77-e83. Kaplan, C. D., Murtezaoglu, F., Ipekoglu, B. & Böke, H., 2013. Weathering of andesite monuments in archaeological sites. Journal of Cultural Heritage, Volume 14S, pp. Pp e77-e83. Kordatos, E. Z. et al., 2013. Infrared thermographic inspection of murals and characterization of degradation in historic monuments. Construction and Building Materials, Volume 48, p. Pp. 1261–1265. Kormann, A. C., Portella, K. F., Pereira, P. N. & Santos, R. P., 2003. Study of the performance of four repairing material systems for hydraulic structures of concrete dams. Ceramica. Liu, Z., Deng, D. & De Schutter, G., 2014. Does concrete suffer sulfate salt weathering?. Construction and Building Materials, Volume 66, pp. Pp. 692-702. Lourenco, P. B., Luso, E. & Almeida, M. G., 2006. Defects and moisture problems in buildings from historical city centres: a case studyin Portugal. Building and Environment, Volume 41, pp. Pp. 223-234. Matthews, S. L., Ueda, T. & Vliet, A. B.-v., 2012. Conservation of Concrete Structures in fib Model Code 2010. London, CRC Press, pp. Pp. 201-202. Md Nor, N. et al., 2014. Diagnostic of fatigue damage severity on reinforced concrete beam using acoustic emission technique. Engineering Failure Analysis, Volume 41, pp. Pp. 1-9. Moropoulou, A. et al., 2013. Non-destructive techniques as a tool for the protection of built cultural heritage. Construction and Building Materials, Volume 48, pp. Pp 1222-1239. Ozga, I. et al., 2013. Pollution impact on the ancient ramparts of the Moroccan city Salé. Lournal of Cultural Heritage, Volume 14S, pp. Pp. S25-S33. Rainieri, C., Fabbrocino, G. & Verdarame, G. M., 2013. Non-destructive characterization and dynamic identification of a modern heritage building for serviceability seismic analyses. NDT&E International, Volume 60, pp. Pp. 17-31. Raupach, M. & Büttner, T., 2014. Concrete Repair to EN 1504: Diagnosis, Design, Principles and Practice. Northwest: CRC Press. Sbartaï, Z.-M., Breysse , D., Larget, M. & Balayssac, J.-P., 2012. Combining NDT techniques for improved evaluation of concrete properties. Cement & Concrete Composites, Volume 34, pp. Pp. 725-733. Sorace, S. & Terenzi , G., 2013. Structural assessment of a modern heritage building. Engineering Structures , Volume 49, pp. Pp. 743-755. Soudki, K. A., 2001. Concrete Problems and Repair Techniques. Ontario, Canada: University of Waterloo. Tapete, D. et al., 2013. Integrating radar and laser-based remote sensing techniques for monitoring structural deformation of archaeological monuments. Journal of Archaeological Science, Volume 40, pp. Pp 176-189. Tashan, J. & Al-Mahaidi, R., 2014. Detection of cracks in concrete strengthened with CFRP systems using infra-red thermography. Composites: Part B, Volume 64, pp. Pp. 116-125. Temizer, T. et al., 2013. 3D documentation of a historic monument using terrestrial laser scanning case study: Byazantine Water Cistern, Istanbul. Strasbourg, International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Valenca, J. & Julio, E., 2010. Conservation Requirments for Concrete Heritage. The case of the Buildings of the Fundacao Calouste Gulbenkian in Lisbon. Guimaraes, CRC Press, pp. Pp. 439-444. Viles, H. G. A. G. S. &. L. J., 2011. The use of the Schmidt Hammer and Equotip for rock hardness assessment in geomorphology and heritage science: a comparative analysis. Earth Surface Processes and Landforms, pp. Pp. 320-333. Yüceer, H. & Ipekoglu, B., 2012. An architectural assessment method for new exterior additions to historic buildings. Journal of Cultural Heritage, Volume 13, pp. pp. 419-425. Read More