Cao Yongkang told the reporter that "small beam and dense column plate quick-loading room" belongs to the category of reinforced concrete structure system. During construction, a large number of perforated wall panels are installed on the foundation ring beam first, and then a reinforced concrete frame is built, which is an integral frame composed of core columns and ring beams (foundation ring beam, interlayer ring beam and floor ring beam). Due to the small cross section of the frame, the thickness of the ring beam does not exceed the thickness of the wallboard, the cross section of the core column is consistent with the cross section of the plate hole, and the spacing inside the wall is small. Furthermore, the wallboard is embedded between the upper and lower ring beams and the left and right core columns, and the beams, columns and floors are mutually anchored, supported and restrained, so that the weight of the upper structure is pressed on the interlayer ring beams, transferred from the ring beams to the core columns and porous wallboard, and then transferred to the foundation. The wallboard not only plays the role of enclosure, but also has the function of bearing. However, the common brick-concrete structures, reinforced concrete structures and steel structures in the market are constructed with reinforced concrete frames first, and then light wallboard is installed. All the loads of the building are borne by the reinforced concrete frame, and the lightweight slab is non-load-bearing and only plays the role of enclosure and spacing. "Small beam dense column" system overcomes this defect, so it is also called "small beam dense column porous wallboard composite load-bearing structure system."
Since the system was introduced to the market on 200 1, it has been used in factories, workshops, farmhouses and other buildings in Beijing, Lintong County, Shandong Province, Jixian County, Tianjin and Fuxin City, Liaoning Province. , especially villa houses in small towns. The feedback information shows that the system has the advantages of fast construction speed, low cost, excellent earthquake resistance, fire prevention, waterproof and windproof performance, and is especially suitable for building low-cost, simple, energy-saving, safe and comfortable houses, and is an ideal choice for future residential buildings.
How did Cao Yongkang, who has been engaged in building materials research for a long time, enter the unfamiliar field of building structure? Professor Cao told two major events that touched his heart. First, in the Tangshan earthquake of 1976, there was a saying that "a sad brick is a deadly board". Most local houses in Tangshan are brick-concrete structures, the load-bearing walls are solid clay bricks, and precast prestressed concrete hollow slabs are used as floors or roof slabs. They are simply placed on brick walls. Under the action of earthquake force, brick walls and floors collapsed, causing heavy casualties.
Thirdly, in the early 1990s, Cao Yongkang, as a senior expert in the field of national wall materials research, received China's diplomatic envoys in Papua New Guinea island countries, Thai builders, a delegation from the Science and Technology Committee of the Vietnamese government and Malaysian Chinese businessmen, who proposed to build low-cost housing that could meet the needs of the public and accommodate a large number of refugees. At that time, due to the limitation of technical level and production capacity, we could not come up with supporting production equipment, production technology and design methods, and finally failed to reach an agreement. Unfortunately, Cao Yongkang's mind sprouted the idea of building a cheap, safe and comfortable fast-loading room with load-bearing lightweight porous wallboard.
During this period, GRC series porous wallboard (including cement expanded perlite mortar wallboard, ceramsite concrete wallboard, pumice concrete wallboard and industrial ash wallboard) presided over or participated in by Cao Yongkang has made gratifying progress. In Cao Yongkang's view, as long as the strength and density of porous wallboard are improved and the supporting structural system is developed, the porous wallboard will develop from inner wall to outer wall and from non-load-bearing wall to load-bearing wall, which will be the way out for the development of wallboard. He thought so and did so.
1In September, 1998, Cao Yongkang, on behalf of China Building Materials Society, recommended to the Ministry of Science and Technology and the Ministry of Construction the proposal of "Practical Wall Material Technology for Rebuilding Homes", and formally put forward the feasibility analysis of "Liang Xiao Dense Column-slab Fast-loading House", which was highly appreciated by the leaders of the two departments and experts attending the meeting, and requested to be put into practice as soon as possible. In 200 1 year, the house of this system really stepped onto the big stage of architecture, and the industry cheered. Following the application in Beijing, Tianjin, Shandong, Liaoning and other places, developers in Shanghai, Guangdong, Fujian, Guangxi and other regions also expressed strong interest in this and demanded to adopt it one after another. But so far, because the system has not been included in the design specification and construction atlas, the promotion speed is slow.
With the rapid development of light steel structure building technology in China, the structural building of "small beam, dense column and plate-type quick-loading room" has attracted the attention of relevant departments. Cao Yongkang is convinced that the fast-loading house will eventually play its due role in the construction market.