Research Of Amino-superplasticizer Synthesize And Modify Cement-concrete Performance

At present the application of sulfonated naphthalene formaldehyde condensate, the main kind of high-range water-reducing agent is limited in preparing pumping concrete and HPC due to its low flowability at low water cement ratio and large slump loss with time elapsed. A kind of superplasticizer of sulfamic acid series is a new superplasticizer with good prospect, which can provide concrete high flowability good durability and low slump loss.A new high-range water-reducing agent AF, which is amino sulfonic acid-based, had been synthesized with sodium sulfanilate, phenol, urea and formaladehyde as the main materials in this dissertation. Based on principles of molecular design, aminosulfonic-based superplasticizer was synthesized by means of controlling reaction conditions such as monomermol ratio, strength of solution. As results of monomermol ratio of sodium sulfanilate and phenol is 1:1.2, monomermol ratio of ( mixture of sodium sulfanilate and phenol ) and formaldehyde is 1:1.15, strength of solution is 33%, perfomance of AF is the best.The IR spectrum of AF indiicates that the strong bangs at 3406cm^-1 (N-H and O-H superposed peak) , 1602 cm^-1,1500 cm^-1 (benzene ring) , 1182 cm^-1 (C-N) , 1126 cm^-1, 1042 cm^-1 (S-O) are the characteristic peaks of AF.Comparing with the widely-used high-range water-reducing agent NF, AF can render cement paste with higher fluidity and has better water-reducing property. Water of the cement paste reached as high as 22% when 0.6% AF was added, while that of NF is only 13.6%. AF also has better flowability retention, Even when water cement ratio was 0.29 and 0.3% AF was added, cement paste fluidity was still up to 225 mm, while that of NF is only 138 mm. When 0.5% AF was added to cement paste, the slump-loss in 2h was reduced greatly. While that of NF is as high as 58.1%. AF has very strong delayed coagulation, The initid and final setting time of cement paste treated with AF prolong 215 min and 191 min respectively than that of untreated. AF has setting-retarded effect, but it doesn't influence the early compressive strength of the concrete. When 0.5% AF was added to concrete, the water reduction could be as high as 20.8% and 3d,7d,28d compressive strength ratios of concrete were 148.5%, 151.7%, 129.9%respectively which exceeded the national standard specifications for...