Notification on the Test Results of the Quality Issues in the Underground Garage of the Kapok Garden Community on Ocean Flower Island Circulated Online

Regarding the quality issues in the underground garage of the Kapok Garden Community on Ocean Flower Island circulated online, our bureau attaches great importance to the matter. Building on the preliminary testing work, we commissioned China National Inspection and Testing Holding Group Hainan Co., Ltd. to conduct targeted expanded testing of the underground garage of the Kapok Garden Community on Ocean Flower Island. Based on the results of both testing phases and the opinions of the expert panel, the test results are hereby notified as follows:

1. On the question of whether "sea sand" was used in the concrete of the underground garage walls and columns"

In order to more comprehensively analyze and investigate whether "sea sand" was used in the concrete of this project, this testing was conducted in accordance with the strict testing category in the national standards. A total of 100 core samples were drilled from components in areas with rebar corrosion for chloride ion content testing. The sampling locations included the upper and lower parts, outer sides and centers of walls and columns, covering a larger and more evenly distributed range. The test results show that, except for 3 test points on the lower outer sides of the walls and columns where chloride ion content exceeded the standard requirements, the other 97 test points all met the standard requirements. However, the chloride ion content in the concrete on the lower outer sides of the columns was significantly higher than in other parts; from top to bottom and from inside to outside of the components, the chloride ion content showed a clear increasing trend. Based on a comprehensive analysis of the test results and the pouring process, it was judged that the excessive chloride ion content was affected by external factors, gradually penetrating from the outside of the concrete into the interior. No use of "sea sand" was found in the concrete of the walls and columns of the underground garage of the Kapok Garden Community.

2. On the issue of "spalling of some concrete protective layers and rebar corrosion"

The severely damaged area of the underground garage of this project is located at the lowest point of the Kapok Garden Community project. In the suspended-construction area, the openings in the underground garage roof slab were not sealed, allowing external water to directly enter the damaged area of the underground garage. Testing showed that the chloride ion content in water samples from the sump pit in the underground garage area where column damage was concentrated was at a high concentration. The lower parts of the columns were eroded by water containing high concentrations of chloride ions; the chloride ions penetrated into the concrete, causing the rebar to corrode and expand, and the protective layer to spall. In addition, this area was not properly put into use, and the ventilation and drainage facilities were not operating; the high air humidity and high temperature accelerated the rebar corrosion.

3. On the issue of "concrete strength"

For concrete strength testing, the testing scope was expanded in the most severely damaged area of the underground garage this time. A total of 72 components were sampled in 3 batches and tested using the rebound core-drilling method. Except for one inspection batch whose estimated concrete strength was 97.1% of the design value, all others met the design requirements. Based on the test results, upon expert analysis and review by the design unit, it was determined that the current concrete strength of the underground garage walls and columns meets the design verification requirements. However, engineering measures still need to be taken to rectify the damaged components in light of the results of both testing phases.

4. Next steps

Our bureau will continue to monitor and track the matter, urge the relevant units to expedite the formulation of a scientific and effective rectification plan, and solidly carry out the rectification work to effectively safeguard the legitimate rights and interests of homeowners.

Danzhou Municipal Housing and Urban-Rural Development Bureau

June 15, 2024

Event Recap

Starting in early March this year, homeowners of the Kapok Garden Community on No. 3 Island of Ocean Flower Island continuously reported and complained through platforms such as the "Leadership Message Board" and the 12345 hotline about problems in the community's underground garage, including large-scale cracking of columns and load-bearing walls, concrete pulverization and spalling, and exposed and severely corroded rebar. Some homeowners suspected that the contractor had illegally used sea sand in construction and worried about safety hazards.

Load-bearing wall of the underground garage of the Kapok Garden Community on Ocean Flower Island. Photo by Chen Biaozhi / China Real Estate News

"In just a month or two, we found that the problems in the underground garage were getting more and more serious," a homeowner of the Kapok Garden Community told a China Real Estate News reporter. They had discovered the relevant problems in the underground garage as early as the beginning of this year, and later, as more and more problem locations were found, they sensed the severity of the issue.

Since the load-bearing columns and walls of the underground garage are the foundation supporting the entire high-rise buildings, residents worry that the worsening "danger" will seriously affect the structural safety of the entire high-rise buildings, thereby posing a huge threat to residents' personal and property safety.

Photos and video materials provided to reporters by community homeowners show that when a homeowner lightly kicked with the tip of a toe, large chunks of concrete fell off many load-bearing columns and walls in the underground garage, exposing rusty rebar; when scraped with a finger, the surface of the rebar turned into brown powder.

According to Upstream News, Mr. Yu, who works in Shenzhen, told the reporter that he spent 980,000 yuan to purchase a 92-square-meter fully furnished apartment in Building 428. "Most of the people here are middle-aged and elderly people from various places who come to Hainan to spend the winter. In winter, the occupancy rate is estimated to be 20 to 30 percent, with more than 3,000 homeowners and about 10,000 people; there are fewer people in summer."

It is reported that because of its good environment, the Kapok Garden sold briskly when it opened, and in the end, people could only secure an apartment by drawing lots.

"I originally wanted to buy a home in Hainan to enjoy my later years, but now I live in constant fear every day," said Ms. Wang, one of the first homeowners in the Kapok Garden to discover the cracking of the underground garage columns. She told an Upstream News reporter that in December 2023, she and several other homeowners wandered into the underground garage and found that some columns showed serious signs of damage and cracking. "The scene was truly shocking. In Building 421, which was suspended and only the underground garage was built, many load-bearing columns had cracks of varying degrees and signs of wall surface spalling. Due to the severe spalling, the rebar inside many columns was exposed and showed signs of rust."

Spalling on the outer walls of load-bearing columns and rusted rebar in the underground garage of the Kapok Garden. Photo provided by interviewee / Upstream News

"In addition, we also found peeling ceilings, bulging on some walls, water seepage on the ground, cracked floors, and corroded ventilation openings," Ms. Wang said. "Although these problems mostly exist underground in the buildings where construction has been suspended, most of the community's underground garages are interconnected, so when a problem occurs in one place, the sense of safety in other buildings disappears as well."

Mr. Yu said, "Some of the homeowners are retirees from the construction industry and design institutes. They suspect that sea sand was used during construction and that the relevant buildings are 'sea sand buildings.' But because this was not a comprehensive inspection but sampling testing, everyone is still only suspicious."

On May 12, the Housing and Urban-Rural Development Bureau of Danzhou City, Hainan Province, issued the "Notification on the Quality Issues in the Underground Garage of the Kapok Garden Community on Ocean Flower Island Circulated Online," stating that it attached great importance to netizens' reports of concrete protective layer spalling and rebar corrosion in the underground garage of the Kapok Garden Community on Ocean Flower Island. It had organized an expert panel to inspect the site and would commission an authoritative third-party testing agency to conduct testing; based on the test results, it would organize relevant experts to deliberate and formulate a scientific and effective disposal plan to properly resolve the issue.

On June 15, the Housing and Urban-Rural Development Bureau of Danzhou City, Hainan Province, issued the "Notification on the Test Results of the Quality Issues in the Underground Garage of the Kapok Garden Community on Ocean Flower Island Circulated Online." The notification stated that no use of "sea sand" was found in the concrete of the walls and columns of the underground garage of the Kapok Garden Community. The columns were eroded by water containing high concentrations of chloride ions; the chloride ions penetrated into the concrete, causing the rebar to corrode and expand and the protective layer to spall. In addition, the high air humidity and high temperature accelerated the rebar corrosion.