Study On The Workability Of High-Performance Concrete With Compound Mineral Admixtures

Along with the development of modern concrete technology, the durability of concrete getsmore and more attention. Workability design and durability design has become the core ofmodern concrete technology. This thesis is about compound mineral admixtureswith steel slag powder, fly ash, blast furnace slag power and siliceous dust, and to take part ofcement, for the sake of making concrete. Study the workability of the HPC that based on the testdata that analyses the water-binder ratio, sand ratio, super-plasticizer type and dosage andmineral admixtures dosage, which can influence the workability of the HPC. Choose greatworkability of concrete proportion, mixing concrete, and make study of compressive strength,the penetration resistance of anti-chloride ions, carbonation resistance, microstructure and so on,verifying a good work performance can makes a preferable durability of concrete. The researchwork and the main results of this paper are as follows:(1) Study the mineral admixture that has impacted on the flow property of cement mortar,which lies foundation of later research on the workability of concrete. The results show that flyash, steel slag powder and furnace slag power can improve the flow properties of cement mortar,nevertheless, siliceous dust will lessen the flow properties of cement mortar. Besides, thecompound mineral admixtures can effectively ameliorate the flow properties of cement mortar.(2) Pick water-binder ratio, sand ratio, compound mineral admixtures dosage andsuper-plasticizer dosage as major factors, through the orthogonal experiment on studying theimpact of various factors on the workability of HPC, The results show that the super-plasticizerhas the biggest influence, water-binder ratio is the second one, mineral admixtures dosage alsohas corresponding impact.(3) The research results of super-plasticizer reveals that polycarboxylic acid super-plasticizeron the aspect of reducing concrete slump and the effect of the loss is better thanNaphthalene series super-plasticizer.(4) The results of concrete compressive strength test shows that mixing blast furnace slagpower and fly ash can improve28-day compressive strength of concrete, mixed withsteel slag powder will reduce the compressive strength; However, the compound admixture canenhance28-day compressive strength of concrete effectively.(5) Through testing the penetration resistance of concrete anti-chloride ions, it displays thatcombined with the mineral admixtures will improve the28-day penetration resistance of concreteanti-chloride ions, the hybrid mineral admixtures also can effectively boost the28-daypenetration resistance of concrete anti-chloride ions. (6) The test results of concrete carbonation resistance indicates that adding the mineraladmixtures, which can result in lowering the resistance to carbonizing of concrete, but siliceousash is expert at improving the28-day resistance to carbonizing compared with other admixtures.The complex mineral admixtures-can enhance the28-day resistance to carbonizing ofmono-mineral admixture concrete.(7) The results of mercury injection test give evidence of the complex mineral admixturesthat improve the microstructure of concrete efficiently.