The Impact of Local Industrially Produced Metakaolin on Both Cement And Concrete Reinforcing Steel Physico-mechanical and Corrosion Resistance Properties

Document Type : Original Article


1 Housing and Building National Research center (HBRC)

2 Housing & Building Research Center

3 Housing and building research center

4 Housing & Building National Research Center (HBRC), Egypt

5 Ain Shams University, Egypt.


Metakaolin (MK) is one of the innovative clay products developed in recent years. It is produced by the calcination of natural kaolin clay, thus, creating an amorphous, reactive product (MK). As a result of the high cost of pozzolanic materials investigation made the suitability of using such local MK as a pozzolanic material in concrete for constructional work unavoidable. The investigation disclosed that the industrially produced MK behaves as a pozzolanic material, thus, consuming part of the Ca(OH)2 resulting from cement hydration forming extra – calcium silicate hydrate (CSH). For preparing cement mixes (for different utilizations – other than concrete) incorporating MK as cement replacement using physico- mechanical tests like Compressive strength, setting time, Differential thermal analysis (DTA) also using electrochemical measurements to test the corrosion resistance behavior, The significant results appear that 15% MK is the optimum dosage (yielding higher pozzolanic effect as well as filler effect). The dosage of 10% MK, as cement replacement ratio in plain (Non-reinforced) concrete, is considered the optimum dosage, manifesting higher compressive strength as well as higher resistance to elevated temperatures. For reinforced concrete, 15% MK is the optimum ratio to be used, as a cement replacement, as long as maintaining the steel reinforcement passivity as well as counteracting the penetration of aggressive ions through concrete is concerned. The locally produced MK could be an excellent substitute for silica fume (SF) as a pozzolanic material in concrete.


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