Huynh Trong Phuoc *

* Correspondence: Huynh Trong Phuoc (email:

Main Article Content


This paper studies the possibility of using a mixture of class-F fly ash (FA) and residual rice husk ash (RHA) for producing unfired building bricks (UBB) with the application of densified mixture design algorithm (DMDA) method. In this investigation, little amount of cement (5–10%) was added into the mixtures as binder substitution. Especially, unground rice husk ash (URHA) was used as a partial aggregate replacement (10–20%) in the mixtures. By following Vietnamese standard (TCVN 1451:1998), solid bricks of 220×105×60 mm in size were prepared for testing hardened properties including compressive strength, flexural strength, water absorption, and bulk density. The forming pressure of 35 MPa was applied to form the brick samples in the mold. Test results reveal that all of the brick samples achieved good mechanical properties. Additionally, compressive strength, flexural strength, and water absorption of brick samples were respectively in the range of 13.8–19.7 MPa, 2.3–3.3 MPa and 9.7–14.8% while the other properties of the bricks were well-conformed to corresponding Vietnamese standards. Furthermore, it was definitely proved many potential applications of FA and RHA in the production of the UBB.
Keywords: Densified mixture design algorithm, fly ash, rice husk ash, unfired building brick

Article Details


Chen, C., Li, Q., Shen, L., Zhai, J., 2012. Feasibility of manufacturing geopolymer bricks using circulating fluidized bed combustion bottom ash. Environmental Technology. 33(11): 1313-1321.

Chen, Y., Zhang, Y., Chen, T., Zhao, Y., Bao, S., 2011. Preparation of eco-friendly construction bricks from hematite tailings. Construction and Building Materials. 25(4): 2107-2111.

Hwang, C.L., Huynh, T.P., 2015. Investigation on the use of unground rice husk ash for producing unfired building bricks. International Journal of Advances in Mechanical and Civil Engineering. 2(1): 1-4.

Lin, K. L., 2006. Feasibility study of using brick made from municipal solid waste incinerator fly ash slag. Journal of Hazardous Materials. 137(3): 1810-1816.

Malhotra, S.K., Tehri, S. P., 1996. Development of bricks from granulated blast furnace slag. Construction and Building Materials. 10(3): 191-193.

MOC, Ministry of Construction of Vietnam, 1998. Vietnamese standard TCVN 1451:1998 Solid clay bricks. Accessed on 28 June 2016. Available from (in Vietnamese)

MOC, Ministry of Construction of Vietnam, 2009. Vietnamese standard TCVN 6355:2009 Bricks-Test methods. Accessed on 28 June 2016. Available from (in Vietnamese)

MOC, Ministry of Construction of Vietnam, 2011. Vietnamese standard TCVN 6477:2011 Concrete bricks. Accessed on 28 June 2016. Available from (in Vietnamese)

Turgut, P., 2012. Manufacturing of building bricks without Portland cement. Journal of Cleaner Production. 37: 361-367.

Zhang, L., 2013. Production of bricks from waste materials–A review. Construction and Building Materials. 47: 643-655.