At about 16:00 on August 27, a fire broke out in the Kaixuan International Building in Jinpu New District, Dalian. After receiving the alarm, the relevant departments of Dalian Jinpu New District quickly launched emergency plans, and relevant leaders of the province, city, and district, as well as fire and emergency departments, rushed to the scene as soon as possible to coordinate and organize rescues.
During the rescue, Dalian Fire used a 101-meter-elevated platform fire truck to continuously fire at the residual fire.
At the scene of the fire, firefighters held water cannons and stood on the roof not far from the fire to put out the fire, with black smoke billowing around.
As of 23:00 on August 27, the open flame of the building had been extinguished, and the remaining fire was being cleared at the scene, with no casualties.
Why did the fire burn so badly?
First of all, according to the official report, in the afternoon, a household on the 19th floor caught fire. The owner went to the property to ask for help. After the property arrived, the room was full of smoke. If this report is true, then that is to say, the residents and the property have defects in the initial fire fighting and alarm, which has delayed a little time; secondly, this building was opened in 2008 and put into use in 2009. At that time, the building was built. The external wall insulation material may not be a non-combustible material, which also caused the fire to spread along the external wall; third, this building has a corridor on the top, when the fireworks spread to this part, it is easy to accumulate heat and expand the fire.
(When it spreads to the bottom of the corridor, the fireworks accumulate heat)
Why is it so difficult to fight a fire?
After the household fire on the 19th floor, 127 fire trucks and 558 firefighters from 5 fire brigade were dispatched for the fire. Helicopters and the highest 101-meter high jet fire truck in the country were also dispatched. The fire fighting lasted more than 7 hours. , It is very difficult to put out the fire. What is the reason for this?
One is that the burning speed is extremely fast. For fires, the flat burning speed is relatively slow, while vertical burning is extremely fast. Sometimes it takes only a few minutes. When the temperature is reached, there is a bang, and a wall will instantly be involved in burning; The second is that there is no fire extinguishing facility on the outer wall. Since the building's fire-fighting facilities are installed inside, there are no fire-extinguishing facilities on the outer wall. After being activated, there is nothing to extinguish the fire. Third, the fire brigade faces the disadvantage of large-scale fire-fighting and control. On the one hand, it is necessary to organize fire-fighting control in the direction of the outer wall, on the other hand, it must be controlled from the inside to prevent the fire from spreading inward, and on the other hand, it is necessary to search and rescue and evacuate the personnel inside the building. This is necessary for the deployment, on-site organization and coordination of firefighting forces. The commander put forward very high demands. In addition, setting up a position under the building is risky. The falling of burning materials on the outer wall can easily cause personal injury and damage combat vehicles and equipment.
The fire formed a three-dimensional combustion. When high-jet fire trucks are working with water, the parking and working area is small and the location is unfavorable, and the intensity of water supply is difficult to control the fire in a short time.
Some netizens lamented: This kind of insulation layer is covered with gusset, and there is a gap between the gusset and the insulation layer. The fire spreads rapidly along the gap, even if there is a spray, it will not hit the fire; the fire spreads in pieces in the lower part of the corridor, and external control For high-spray vehicles, there are many blind spots for spraying, it is impossible to really block the fire; the corridor between the two towers is directly baked by the lower fire, not only the fire is easy to penetrate into the room, but also the exterior wall building components will quickly deform, forming a large number of Falling objects directly threaten the surrounding personnel and vehicles. So, it's too difficult, too pitted.
Another reason to mention is that around 13:00 that day, a big fire broke out in a market in Dalian. There was a lot of smoke and the subway station was temporarily closed. Many Dalian Fire Fighting Forces put into fire fighting and rescue work. Before the fire was completely extinguished, the landmark building caught fire again, and the fire fighting faced a situation of two-line combat.
In this fire, the firefighters went deep into the fire floor and attacked, braving the fire and smoke on the top floor to control the spread of the fire. It was very hard and dangerous, and paid tribute to them.
Does the fire protection facility play a role?
According to the "Code for Fire Protection Design of Buildings", this building has 31 floors. If it is a super high-rise apartment building, it is a high-rise public building. Even if it is not a super high-rise, the 31-story building is at least 90 meters high and should be classified as a high-rise public building. . The building covers an area of 63,000 square meters. According to the specifications, an automatic fire alarm system, automatic sprinkler system, fire hydrant system, etc. should be installed. After the fire broke out, the property owner asked for help and arrived before confirming the fire and calling the police. Is this Means that the automatic fire alarm system has not been activated or the duty officer in the fire control room has not effectively handled it even though it has activated? Judging from the later fire video, the flame entered the building B and burned, and there is no official announcement about whether the sprinkler system is activated, and further investigation is needed.
The external wall insulation project has been going on for about 30 years. Especially after 2000 to 2014, the external wall insulation of a considerable number of buildings does not meet the requirements of the current regulations. In the event of a fire, there is a risk of spreading throughout the building. Arouse more attention.
Fires caused by or rapidly spreading due to the insulation of external walls occur almost every year...
"Exterior wall insulation" has become a "fire killer" again
Frequent accidents and painful lessons
At 9 o'clock in the evening on December 2, 2019, a fire broke out in the residential area of SR International New City, Hunnan New District, Shenyang City, Liaoning Province. The external wall insulation material caught fire. The fire broke out with a total of 25 floors. The fire was on the outer wall of the 5th floor and above.
▲ "12·2" Shenyang fire accident
On the evening of May 24, 2019, a fire broke out in the Golden Eagle Shopping Center in Nanjing's Xinjiekou business district.
▲ "5·24" Nanjing Golden Eagle Fire Incident
On February 1, 2018, the external insulation material of the Greenland Yuansheng International Office Building in Zhengdong New District, Zhengzhou, Henan Province caught fire.
▲ "2·1" Zhengzhou fire accident
On April 21, 2014, the outer wall insulation layer of the Yidajiete apartment building in Xinghai Square, Dalian City, Liaoning Province caught fire. Smoke billowed in an instant. There were no casualties in the accident.
▲ "4·21" Dalian fire accident
At 14:00 on November 15, 2010, a high-rise apartment building on Jiaozhou Road, Yuyao Road, Shanghai caught fire. Many retired teachers lived in the apartment. By 10:20 on November 19, the fire had killed 58 people.
▲ "11·15" Shanghai fire accident
On the evening of February 9, 2009, a huge fire broke out in the CCTV Television Culture Center under construction. The fire caused a direct economic loss of 160 million yuan, and more than 70 people were held accountable after the accident.
▲ "2·9" China Central Television Fire Incident
Behind the accidents time and time again, it has revealed how bad the fire inspection and acceptance of the current exterior wall insulation materials of construction projects are!
From 2017 to 2018, six ministries and commissions including the Ministry of Public Security and the Ministry of Housing and Urban-Rural Development jointly carried out a six-month comprehensive fire safety management for high-rise buildings across the country. The investigation results of high-rise buildings by local fire departments showed that the fire performance of building external thermal insulation materials did not meet the standards and was used in violation of regulations. Combustible and combustible external thermal insulation materials have become a major fire hazard in high-rise buildings.
What is the current status of external wall insulation?
The results of the site investigation are worrying!
▲ CCTV survey report on "National Comprehensive Fire Safety Management of High-rise Buildings"
Accidents have sounded alarm bells for the industry. The design and construction of building exterior wall insulation materials must comply with national standards and select materials that meet the requirements of fire protection levels. In this regard, it is necessary to study the authoritative interpretation from the fire staff.
▲ "Counselor Wu Talks about Fire Fighting"
6.7.4 (mandatory provisions)
For buildings with densely populated places, the combustion performance of the external thermal insulation materials of the external walls should be Class A.
6.7.5 (mandatory provisions)
For the external thermal insulation system of building exterior walls without a cavity between the base wall and the decorative layer, the thermal insulation materials shall meet the following requirements:
1 Residential buildings:
1) When the building height is greater than 100m, the combustion performance of the insulation material should be Class A;
2) When the building height is greater than 27m but not greater than 100m, the combustion performance of the insulation material should not be lower than B1;
3) When the building height is not greater than 27m, the combustion performance of the insulation material shall not be lower than B2;
2 Except for residential buildings and buildings with densely populated places, other buildings:
1) When the building height is greater than 50m, the combustion performance of the insulation material should be Class A;
2) When the building height is greater than 24m but not greater than 50m, the combustion performance of the insulation material shall not be lower than B1;
3) When the building height is not more than 24m, the combustion performance of the insulation material shall not be lower than B2 level.
6.7.6 (Mandatory provisions)
Except for buildings with densely populated places, the external thermal insulation system of buildings with cavities between the base wall and decoration layer, the thermal insulation materials should meet the following requirements:
1 When the building height is greater than 24m, the combustion performance of the insulation material should be Class A;
2 When the building height is not more than 24m, the combustion performance of the insulation material shall not be lower than B1 level.
After decades of application of external thermal insulation system in China, the three major "pain points" have reached a period of frequent problems, and technological changes in the industry are also imperative.
Three "pain points" of external wall insulation
"Cracking, hollowing, falling off; thermal insulation but not flame retardant; flame retardant can not meet the thermal insulation requirements of energy-saving buildings, which has become the three major'pain points' in the external wall insulation industry."
The "chicken rib effect" of common insulation materials:
The first is insulation mortar. Due to the addition of a large amount of inorganic materials to the thermal insulation mortar, it has the characteristics of non-combustibility, which once filled the gap in the industry and was gradually recognized by the market. Thermal insulation mortar has a large thermal conductivity coefficient, and is mainly used in southern China, which has contributed to building energy conservation.
However, the technical defects of the thermal insulation mortar have gradually emerged: firstly, the thermal insulation mortar must be mixed and stirred on site. It is difficult to supervise and easy to bury hidden hazards due to factors such as the operating level of the workers, the climate environment, and the construction site conditions; secondly, the thermal insulation mortar falls off and cracks. , Water seepage, hollowing and other problems frequently occur, which seriously affect the quality and safety of construction. Finally, by 2020, the total energy consumption of buildings in the whole society must achieve the overall goal of 75% building energy saving, and thermal insulation mortar cannot be achieved.
Aiming at the problems of thermal insulation mortar. Beijing and Jiangsu took the lead in banning the use of thermal insulation mortar in China. Some places followed closely, requiring buildings to prohibit, restrict, and cautiously use thermal insulation mortar.
The second is thermal insulation rock wool. The main component of rock wool is inorganic matter, which has good fire prevention effect. However, the production process of thermal insulation rock wool requires a large amount of ecological energy, and the problem of environmental pollution has been repeatedly exposed. Some rock wool production areas have been named by the Ministry of Ecology and Environmental Protection for many times, and they have been rectified within a time limit. In order to meet environmental protection standards, strong rock wool enterprises continue to improve and upgrade production equipment, eliminate outdated production capacity and technology, resulting in a substantial increase in the cost of thermal insulation rock wool, and the price advantage is no longer obvious.
In addition, ordinary thermal insulation rock wool also has low tensile strength; it is unstable in size under humid and hot conditions, and settlement causes hollowing and shedding; there is connected air between the fiber and fiber of the rock wool bare board, which expands and contracts with heat. Under the action of negative wind pressure, it is easy to be fluffy and swollen.
At the end of 2017, Kaifeng, Henan began to restrict the use of rock wool board thin plaster external wall external insulation system. The person in charge of the Municipal Bureau of Housing and Urban-rural Construction introduced: “The technical defects of domestic rock wool are obvious, mainly in the aspects of tensile strength and water absorption. Due to the hydrophobicity of rock wool, it is easy to form cavities and chalk when applied to external wall insulation. , Falling off and other phenomena, thus failing to achieve the desired thermal insulation effect." In 2019, Hunan Province banned the promotion of the use of rock wool thermal insulation materials, stating: “The external thermal insulation system of rock wool board thin plastered external walls does not meet the climate characteristics of Hunan Province and poses safety hazards; rock wool and glass wool without keel and protective panels The internal insulation system of the product does not meet the standards and poses a hidden danger to human health." In October 2020, Shanghai announced the "Catalog of Materials Used in Construction Projects Prohibited or Restricted in Production and Use in Shanghai (Fifth Batch)": It is forbidden to use the exterior walls of newly built, rebuilt and expanded construction projects as the main insulation system design The use of cement or anchor bolts and the construction process of the combination of the two methods of external wall external insulation system; it is forbidden to design and use rock wool thermal insulation decorative composite board external wall external insulation system on the outside of the external wall of newly built, rebuilt, and expanded construction projects as the main insulation system ; It is forbidden to design and use thermal insulation board as the main thermal insulation system on the outer wall of newly built, rebuilt and expanded residential buildings over 27 meters and public building projects over 24 meters. The area of the decorative composite board should not exceed 1 square meter, and the mass per unit area should not exceed 20kg/m2; it is prohibited to use the insulation board as the main insulation system outside the outer wall of the new, rebuilt, or expanded construction project over 80 meters. It is an A-level thermal insulation decorative composite panel external wall external thermal insulation system, and the area of the thermal insulation decorative composite panel should not exceed 1 square meter, and the unit area mass should not exceed 20 kg/㎡. In addition, other parts of the country have also issued "bans"...
Secondly, organic materials such as XPS polystyrene extruded board, which have become "accomplices" in many fires, have been banned by the industry.
Urgent need for industry "reform"
"The exterior wall insulation industry must first solve the'cheeky' problem, otherwise the incident of falling off and hurting people and objects may become more serious." Many experts expressed anxiously.
Yang Yuzhong, a professional chief engineer of the Energy and Environmental Testing Center of the Chinese Academy of Building Research, pointed out that in the past two to three years, the standards in the field of energy conservation and insulation of external walls have changed greatly. As the requirements for energy conservation in buildings increase, the thickness of the insulation layer of buildings has been correspondingly changed. Increasing, for example, the requirement for external wall insulation of near-zero energy consumption buildings is equivalent to increasing the thickness from 60mm to 80mm to more than 200mm, which brings higher safety hazards to the construction quality of external wall insulation.
“The outer wall insulation layer is getting heavier and heavier, the construction technology is not improved enough, and there is a conflict between insulation and energy saving and firm installation.” Professor Meng Yang of Shandong University of Architecture said, “The current outer wall insulation layer is close to 20 kilograms per square meter. The requirements will also increase, but many workers are accustomed to the original relatively simple operation at the scene, and it is inevitable that some local fixation is not in place."
How to get out of the chaos and predicament of building insulation engineering? The only way out is "material innovation". Not only exterior wall insulation, it involves the entire building insulation system. The shortcomings and hidden dangers of traditional materials in external wall insulation will also appear in the overall metal enclosure system. According to the trend of relevant national policies, the future metal enclosure system will also be slowly abandoned due to many problems caused by traditional materials. . Therefore, the innovation of building insulation materials cannot be delayed. Instead of waiting for the promulgation of national laws and regulations, it is better to start using new green materials recognized by the country now, which not only solves the problems caused by traditional materials, but also avoids forced replacement of new materials in the future. The cost of maintenance and renovation. The R&D team of Yuanchuangxiang (Suzhou) New Material Technology Co., Ltd. is upholding this view. After nine years of hard work, the new product "reflective bubble aluminum heat insulation film" developed by the country has been supervised by the national building energy conservation quality. The inspection center appraisal: the product is lightweight, the weight is not higher than 400g per square meter, the reflectivity is 97%, the thermal conductivity is 0.0436W/(m·K), the tear strength is not less than 24N, and the tensile breaking strength is not less than Below 500N/5cm, the fire retardant is Class A. At present, the product has been strongly recommended by the design institute in East China and North China. The original design of thermal insulation mortar or rock wool board has also undergone a large number of engineering design changes, which has caused great repercussions. It is generally believed that a way out has been found. The dilemma.
Industry insiders also pointed out that with the iterative update of building insulation materials, the country should speed up the improvement and adjustment of relevant policies and regulations, and give the new materials a platform, instead of always spinning around on the original several kinds of insulation wall materials. New materials with mature technology and market approval must be promoted and used as soon as possible. The state should also provide policy encouragement and financial support to enterprises that develop and produce new materials for external wall insulation, so as to promote the formation of a good situation in which the industry is vying for the first R&D and innovation.
At the same time, it is necessary to implement a lifelong accountability system for construction quality as soon as possible. Form a system of accountability of whoever develops, who manufactures, who builds, who monitors, and who accepts, strengthen the sense of responsibility of all departments, and promote the promotion and use of new materials and new products.
Prior to this, the State Administration for Market Regulation issued the "National Key Industrial Product Quality and Safety Supervision Catalog (2020 Edition)", which included exterior wall insulation materials in the National Key Industrial Product Supervision Catalog. It is required that “on the basis of safety assessment, according to the level of product quality and safety risks, measures such as strengthening supervision and spot checks, production licenses, law enforcement and anti-counterfeiting, certification and approval, risk monitoring, and defective product recalls shall be taken by classification.” I believe this will force the insulation wall material industry. , To accelerate the innovation of products and technology.