Increasing the use of non-fired bricks (NFBs) within the building materials sector is a trend in many countries, including Vietnam. Besides saving the clay resources, the area of agricultural cultivation, etc, the use of NFBs in construction also contributes to saving fuel and energy, reducing emissions and environmental pollution, reducing costs, and helping labours not to exposure directly with high temperatures, and others. This not merely opens the path to the development of NFBs towards an eco-friendly building sector but also brings a high economic efficiency.
Breaking barriers thank to many open policies
According to the report of the Building Materials Department - Ministry of Construction, so far, red bricks are still widely used in construction. In order to produce this type of bricks, many materials, non-renewable minerals and fossil fuels will be consumed; they are burnt in manual kilns or tunnel kilns, so CO2 emissions would cause greenhouse effect, and workers have to work in a hazardous environment. In particular, the raw materials used for the production of red bricks are exhausted because the amount of sediment deposited in riversides is not much left, leading to a shortage of raw materials for production.
To replace red bricks, currently, the promotion of using NFBs has been stipulated in many policies such as: Program of developing non-fired building materials according to Decision No.567/QD-TTg; Decision No.1469/QD-TTg of the master plan on development of construction materials in Vietnam to 2020 and orientation to 2030; Circular No.13/2017/TT-BXD regulating the use of non-fired construction materials in construction works; Directive No.10/CT-TTg strengthening the use of non-fired building materials and restricting the production and use of baked clay bricks, etc.
In particular, the goal is to reduce the annual increase in greenhouse gas (GHG) emissions by strengthening the production and use of NFBs in Vietnam, the Ministry of Science and Technology and the Ministry of Construction has implemented the project "Enhancing production and use of NFBs in Vietnam" from 2014 to 2019, this is funded by the United Nations Development Program (UNDP) from the Global Environment Fund (GEF) and other co-funding sources with the aims to reduce the annual rate of greenhouse gas emissions by gradually reducing the use of fossil fuels and soil to make bricks through the increased production and use of NFBs in Vietnam. Direct GHG emissions are estimated at 383 ktonnes of CO2. Indirect GHG emissions are estimated to be 13,409 ktonnes of CO2 accumulated within 10 years after the end of the Project.
Mr Quang Hiep Nguyen, Deputy Director of Construction Materials Department - Ministry of Construction, said that if you want to bring NFBs widely applied in practice, the price must be attractive and information must be given fully to users. Decree No.24a/2016/ND-CP on the management of construction materials has many investment incentives for a project to produce light non-fired building materials (volume of not more than 1,000 kg/m3) with the capacity of a production line at 50,000 m3/year or more; a project of producing concrete bricks (cement bricks - aggregates) with the capacity of a production line at 10 million bricks or more per year. Besides, it is also entitled to investment incentive policies as stipulated in Clause 1, Article 15 and investment support as stipulated in Clause 1, Article 19 of the Investment Law; being supported with technology transfer costs for investment projects that have the technology transfer costs prescribed in Article 9 and Article 39 of the Law on Technology Transfer... "These incentives will help lower production costs and price of products", Deputy Director Quang Hiep Nguyen said.
At the meeting of the Project Steering Committee, which recently took place in Hanoi, Mr Giao Tien Do - Foreman of the Project of Strengthening NFB Production and Use in Vietnam said, the policy framework, standards and development norms of non-fired building materials have been studied and completed through the implementation of the Project. A number of policies, standards, and norms have been issued, contributing to gradually removing barriers and obstacles to bringing NFBs to be widely used in construction works. In particular, the Project Management Board has built 05 sets of training materials; organizing 23 training courses for 1,680 applicants from 63 provinces and cities on the policies and standards of NFBs; design and construction of NFB works; technology for producing autoclaved aerated concrete; technology for producing aggregate concrete bricks, etc.
In addition, the Project has supported the provision of sustainable finance for the application of NFB production technology through lending 9 preferential loan projects with the capital of VND 121 billion, lending 9 medium- and long-term loan projects with the capital of VND 66.5 billion and 18 short-term loan projects with a capital of VND 380 billion; completed 22 demonstration projects and replicated with a total capacity of 1 billion standard bricks, which directly and indirectly contributes to increasing NFB market share to 28%, the energy saving of 332,690 TOE, GHG emission reductions of 1,816,590 tons of CO2. "A total of 36 businesses borrowed preferential and commercial loans to invest and produce NFBs with a total loan of VND 567.5 billion" - Mr Giao Tien Do shared
The inevitable trend
Emphasizing the benefits brought by NFBs, Deputy Director Quang Hiep Nguyen said that, in addition to saving clay resources and agricultural cultivation area, saving fuel and energy, reducing emissions, etc. NFBs also consumes a significant portion of waste from other sectors such as thermal power, metallurgy, mining, minimizing environmental pollution and waste disposal costs.
Besides, the increase of NFB ratio compared to red bricks is an inevitable trend of many countries, including Vietnam. To produce 1 billion standard red bricks, 1.5 million m3 of clay will be consumed, equivalent to 75 ha of agricultural land (exploitation depth of 2 m) and 150,000 tons of coal, while emissions will be about 0, 57 million tons of CO2 - causing greenhouse effect and other harmful emissions polluting the environment. It is forecasted that construction material demand will reach about 42 billion standard bricks in 2020. If meeting this demand entirely by red bricks, it will consume about 57-60 million m3 of clay, equivalent to 2,800-3,000 hectares of agricultural land; 5.3-5.6 million tons of coal, while emissions will be about 17 million tons of CO2. "Therefore, to meet the demand of building materials with an increase of 10-12%/year, if only using red bricks, thousands of hectares of agricultural land and millions of tons of coal will be consumed each year" - Deputy Director General Quang Hiep Nguyen emphasize.
Also according to Mr Quang Hiep, the development of non-baked building materials production will gradually take advantage of waste sources, help reduce environmental pollution, create green products and green buildings. For a long time, many countries in the world have used NFBs with a very high utilization rate, some countries in the region such as Thailand and Malaysia have the NFB usage up to 70-80%.
However, Deputy Director Quang Hiep Nguyen said that the lack of capital and experience is one of the major barriers for investors in the production, importing technological lines with average level, lack of synchronization. Therefore, technology acquisitions and techniques are not good enough; models of some NFB products are monotonous, not suitable for the market; awareness of investors, design consultants, contractors, consumers about unbaked construction materials is still incomplete, requiring specific technical requirements and construction procedures; many construction units have not complied with the technical instructions, causing defects negatively affecting the efficiency of product use and trust of users.
Assessing the quality of available NFBs, Associate Prof. Dr. Dinh Thien Bach - Director of the Institute of Researching and Applying Tropical Building Materials, National University of Civil Engineering said, to ensure the quality of NFBs, namely concrete bricks, we need to ensure raw materials: cement, aggregate, mineral additives, chemical additives and quality water; reasonable ingredient proportion, ensuring design; mixing process with high uniformity; shaping on the vibration device is well packed; high uniformity of bricks in a batch; maintained in a saturated humid environment until stabilizing volume.
Currently, there are three advanced production lines of concrete bricks with large capacity, including Concrete brick factory of Tan Thanh 9 Company (Thanh Hoa); Concrete brick factory of Tran Chau Company (Ha Tinh); Dai Dung Xanh non-fired brick factory (Ho Chi Minh City). At these three factories, each production shift uses only 3-5 employees. Technological process of producing concrete bricks in these factories, especially the maintenance process is strictly controlled, ensuring stable quality of bricks.
“In Ho Chi Minh City and Hanoi, 100% of the projects funded by the state budget shall use NFBs. In order to increase the NFB acceptance rate in the community, we need to continue propagating the benefits brought about by the use of NFBs and at the same time using modern production lines with high productivity, so the prices of NFBs will be lowered and can be competitive with red bricks in the near future”- Associate Prof. Dr. Dinh Thien Bach said.
According to experts, NFBs are currently grouped into 3 main types including concrete bricks (also called aggregate cement bricks), autoclaved aerated concrete bricks and foam concrete bricks (light bricks). The composition of NFbs, besides adhesives as cement (the ratio of 8 to 10%), also has grit, slag, etc. which are waste from industry, contributing to reduce the possibility of environmental pollution. Light NFBs is suitable for large-scale construction projects and high-rise buildings. In fact, for the current small-scale civil works, especially in remote areas - where the transportation of materials is very difficult, people still combine the use of concrete bricks and red bricks.
The outstanding advantage of NFBs is the lower price by 5 to 10% than that of traditional bricks. In addition, NFBs are produced according to mechanized lines, workers do not have to be in direct contact with high temperatures. The bricks have good soundproof and insulation ability. Lightweight bricks help reduce the cost of foundation structure, bearing parts, beam frames, thereby allowing lowering the cost of the works.