Monument Future - Siegfried Siegesmund

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walls – case study, MATBUD’2018, MATEC Web of Conferences; 163.

      Nogueira R., Ferreira Pinto A. P., Gomes A., Assessing mechanical behavior and heterogeneity of low-strength mortars by the drilling resistance method, Constr. Build. Mater. 68 (2014).

      Nogueira R., Ferreira Pinto A. P., Gomes A., Bogas A., Prediction of compressive strength for heterogeneous mortars from drilling resistance data, Int. J. Archit.Heritage (2018), https://doi.org/10.1080/15583058.2018.1547800.

      Pamplona M., Kocher M., Snethlage R., Aires Barros L. (2007) Drilling resistance: overview and outlook. Z. dt. Ges. Geowiss., 158/3, p. 665–676.

      Pelà L., Roca P., Aprile A., Combined in-situ and laboratory minor destructive testing of historical mortars, Int. J. Archit. Heritage 12 (3) (2018) 334–349, https://doi.org/10.1080/15583058.2017.1323247.

      Penetrometro malta RSM 1.0 user manual – 2015. www.drcitalia.it/en, (February 5, 2017)

      UNI EN 1015-11, 2019 – Determinazione della Resistenza a flessione e compressione della malta indurita. Ed. UNI (Ente Nazionale Italiano Unificazione) Milano 2007.

      UNI EN 12504-1, 2019 – Prove sul calcestruzzo nelle strutture – Parte 1: Carote – Prelievo, esame e prova di compressione. Ed. UNI (Ente Nazionale Italiano Unificazione) Milano 2019.

      UNI 12390-13, 2013 – Prove sui calcestruzzi. Determinazione del modulo di elasticità secante in compressione. Ed. UNI (Ente Nazionale Italiano Unificazione) Milano 2013.

      UNI EN 12390-6, 2010 – Prove sul calcestruzzo indurito – Parte 6: Resistenza a trazione indiretta dei provini. Ed. UNI (Ente Nazionale Italiano Unificazione) Milano 2010.

      Yang S., Gu R., Cao S., New local compression test to estimate in situ compressive strength of masonry mortar, J. Test. Eval. 44 (1) (2016) 67–76, https://doi.org/10.1520/JTE20130088. ISSN 0090-3973.

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       ULTRASONIC TESTING OF THE DOLOMITE MARBLE STATUE OF SOONG CHING-LING WITH RESPECT TO THE DEPTH OF CRACKS AND DETERIORATION STATE

      IN: SIEGESMUND, S. & MIDDENDORF, B. (EDS.): MONUMENT FUTURE: DECAY AND CONSERVATION OF STONE.

       – PROCEEDINGS OF THE 14TH INTERNATIONAL CONGRESS ON THE DETERIORATION AND CONSERVATION OF STONE –

       VOLUME I AND VOLUME II. MITTELDEUTSCHER VERLAG 2020.

       Abstract

      The marble statue of Soong Ching-ling stands in the memorial square of Soong Ching-ling cemetery in Shanghai, China. The statue has been inaugurated in 1984 and is a Chinese National Monument. Since 2014 many micro cracks appeared on the surface, especially on the head of the statue. To evaluate the deterioration 174condition of the statue and the depth of the cracks, non-destructive ultrasonic technology was applied. The deterioration state was tested by the USCT (Ultrasonic Computed Tomography) method and the depths of surface cracks were determined.

      Based on the USCT, there were no penetrative severe cracks. The depth of the superficial cracks on top of the head was not more than 50 mm. However, a clearly deteriorated, shell-like zone with a thickness from 10 to 50 mm was found around the head. Fifteen micro cracks were detected and the depths of those cracks ranged from 0 to 68 mm. The results provided fundamental information to work out a preservation concept.

      Keywords: Soong Ching-ling statue, dolomite marble, ultrasonic detection, USCT, cracks

       Introduction

      Madam Soong Ching-ling (June 1893–May 1981) was the wife of Mr. Sun Yat-sen, the founder of the Republic of China. She had been honorary Chairlady of the Peoples’ Republic of China.

      The marble statue of Soong Ching-ling stands in the memorial square of Soong Ching-ling cemetery in Shanghai, China (Fig. 1). The statue was inaugurated in 1984. It stands 2.52 m high on top of a granite basement, which is 1.1 m high above the ground level.

      The statue is composed of 4 pieces of Fangshan Hanbaiyu, a valuable and famous dolomitic marble from Fangshan, Beijing.

      Mineralogically it consists of approximately 92–97 % dolomite(CaMg(CO3)2), minor amounts of quartz and muscovite have also been identified.

      Since 2014 many micro cracks appeared on the surface, especially on the head of the statue (Fig. 2).

      Inspection under the in-situ microscope shows different stages of disintegration of the crystal fabric on the surface.

      Figure 1: Marble statue of Ms. Song in Shanghai.

      Figure 2: Progressive crack on the head.

      A comprehensive conservation and compatible maintence concept is needed to check the weathering process. But first of all, the deterioration condition of the statue and the depth of the cracks had to be evaluated. Non-destructive ultrasonic technology was applied. The deterioration condition was tested by USCT method and the depths of surface cracks were determined.

       Principle and method of ultrasonic testing

       Ultrasonic wave and natural stone

      Ultrasonic waves are mechanical waves which can spread in solid, liquid and gas mediums. They may be differently attenuated when propagating in different

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