Billion-dollar project, new bricks " lose" thousands of years of bricks
The project to restore the North Tower and the Middle Tower, in the Cham Khuong My Tower cluster (in Tam Xuan commune, Da Nang) has been implemented since October 2019, with a total investment of 12.6 billion VND, from the State budget.
The construction unit is the Institute of Construction Science and Technology (Ministry of Construction), the investor is the Quang Nam Provincial Investment and Construction Project Management Board (old). The project will be completed by the end of 2022.
After the restoration, there was a phenomenon of salinity and moss on the surface of the restoration bricks. Up to now, the bricks are unusually rotten, peeling off layers like powder, and just a light touch will cause crumbs.
Explaining the situation of newly restored billion-dollar bricks deteriorating faster than the ancient bricks that have existed for thousands of years, Mr. Pham Hong Truong - Head of the Relic restoration Department, Central Center for Construction Technology Development (Institute of Science and Technology of the Ministry of Construction) affirmed that this is an "object phenomenon, cannot be completely handled" and the restored bricks are not the cause - because the bricks left outdoors "neverare soil, put in the tower are soil immediately".
The technical report of the Institute of Science and Technology of Construction also concluded that "a large source of salt accumulated on ancient bricks" spread to new bricks with rainwater - moisture; the old adjacent area - was most strongly attacked. Therefore, salt can reduce the durability of brick tiles, temporarily destroying the surface of the relic building block.
The construction unit affirmed that this is a common phenomenon in Cham tower along the coast. The thorough handling of this problem takes a lot of time and money, but in urgent conditions, the project worth 12.6 billion VND only focuses on reinforcing the body and preventing immediate collapse.
Broken bricks due to objectivity?
At the time the project first experienced surface salinity (5 months after restoration), the Quang Nam Provincial Investment and Construction Project Management Board (old) affirmed that salt only caused "aesthetic loss, not affecting the structure" and only required the contractor to replace the damaged bricks - that is, repair the tops.
However, as soon as the project had just expired its warranty period, the project showed signs of deterioration when the newly restored bricks were rotten and deformed, raising concerns about having to support a massive tower block of more than 20m.
About 20 years ago, research groups (Japan and the locality) pointed out that the base of Khuong My tower has an underground water mach; the results of the 4-6m deep drilling showed that the water flow passed through the tower foundation - an unfavorable factor, forcing the restoration project to treat the entire roof to the foundation if it wanted to overcome the long-term moisture - salt phenomenon.
Mr. Dang Khanh Ngoc - Director of the Institute of Monuments Conservation under the Ministry of Culture, Sports and Tourism, emphasized: "Each tower has a different conservation solution", it is impossible to just " handle the tower body" but ignore the roof and foundation. To effectively prevent salt and moisture (which can lead to brick mud), there must be a comprehensive project, while treating rainwater absorbed from the roof and groundwater from the ground up.
A thousand-year-old relic, but short-term restoration solution
In the minutes of the meeting on the implementation of the Cham Khuong My Tower renovation project (March 2024), specialized units of Quang Nam (old) and the Central region all issued warnings: moisture caused by groundwater, leachate roofs, salt accumulated on ancient bricks, coastal environment... The technical requirement is to treat the whole and maintain it periodically.
However, the restoration project of the Cham Tower with a capital of 12.6 billion VND still chose a quick - compact - anti-collision approach, leaving the original part unused. The result was salinity after only 5 months, the bricks were stuck after 2 years, while the controversy over responsibility had not yet been resolved.
In addition to materials, Khuong My Tower also faces the risk of architectural deformation due to subjective intervention. The letter of comments dated September 14, 2022 by researcher Tran Ky Phuong sent to the professional agency warned that the construction of manhole covers the inner wall of the Central Tower - which is a characteristic of the cave shape in Cham architecture - damages the original state. Warnings were issued before the acceptance date but were not properly responded to.
Responding to the question of Lao Dong reporter - why the restoration project of Cham Tower relic was not assigned to a unit with deep expertise in restoration of relics as the investor but assigned the Management Board of the old Quang Nam Provincial Construction Investment Project, the leader of this Board said: According to Decree 59/2015/ND-CP on the management of the construction investment project of the Management Boards of the Department of Culture, Sports and Tourism merged into the Project Management Board and the Board with a team of cultural specialists to continue managing this area. The Board also hires project design units of the Ministry.
