( 1) naphthalene sulfonate formaldehyde condensate (naphthalene superplasticizer)
Naphthalene superplasticizer is aromatic sulfonate formaldehyde condensate. The main component of naphthalene superplasticizer naphthalene sulfonate and formaldehyde or homologues of the condensate, which belongs to the anionic surface active agent.
Naphthalene superplasticizer structure characteristics is hydrophobic backbone for methylene connecting double or polycyclic aromatic hydrocarbons, a hydrophilic functional group is not even in aromatic ring - SO3M.
Naphthalene series superplasticizer according to their products in Na2SO4 content, can be classified as high concentrated model product (Na2SO4 content < 5% ) and low concentrated model product ( Na2SO4 > 5% ppm ). Spot agitate concrete, general mixed with powdered additive, Na2SO4 content has little effect on. In commodity concrete, using liquid additive, low concentration naphthalene products in low temperature is easy to generate Na2SO4 crystallization, the impact of measurement accuracy and usage effect. In order to reduce the product of crystallization degree and wipe out crystallization, production plants generally use the KOH, Ca ( OH ) 2 instead of NaOH neutralization, or increase the low temperature filtration procedure Na2SO4 removal, the production of high concentration of naphthalene series superplasticizer.
Naphthalene series superplasticizer in the recommended dosage of water reduction rate is in commonly 15% ~ 25%, basically do not affect the setting time of concrete air content, low ( < 2% ), the more obvious effects of improving the strength of concrete.
Naphthalene superplasticizer is associated with cement adaptability problems, sometimes loss of concrete slump faster, this and superplasticizer sulfonated degree itself, degree of polymerization, and the ion species, the content of Na2SO4, mixed time state, dosage and adding method, therefore, in commodity concrete with the naphthalene water reducing agent generally at the same time the composite retarder, entraining such fractions were modified, be called pumping agent products.
( 2) melamine formaldehyde condensate sulfonates ( melamine superplasticizer )
Melamine superplasticizer is a water-soluble polymer, which is the main component of sulfonated melamine formaldehyde condensate, which belongs to the anionic, early strength, non air-entraining water-reducing agent, water reducing rate of up to 25%. Product representation of the German Melment, Japan NL-4000, Sweden's Peramin SMF and China SM. According to the German expert Professor Plank statistics, naphthalene and melamine is currently the world's most widely used high efficiency water reducing agent.
Melamine superplasticizer belongs to low the air-entraining, no retarding effect, reduction of water equivalent of naphthalene series superplasticizer, on the concrete to strengthen effect is good, but adding traditional melamine superplasticizer after loss of concrete slump faster. Due to its colorless and low air entraining features, suitable for dry powder mortar, color brick road and clear water concrete production.
In 2004, China Building Materials Academy developed a cost-effective new melamine superplasticizer, its modified technology route of revised, with melamine as the main raw material, via hydroxyl methylation reaction activation of the active functional groups generate methylol melamine, and then introduce other prepolymer monomer, increase may be associated with a melamine condensation monomer, change of condensation products the molecular structure, than the traditional melamine superplasticizer better performance of the new melamine superplasticizer.
( 3) amino sulfonate ( sulphamate series superplasticizer)
Amino sulfonate superplasticizer for amino benzene sulfonate - phenol - formaldehyde condensation product, also known as single ring aromatic type superplasticizer, mainly refers to the polymer hydrophobic backbone phenyl and methylene alternately connected together, and in the main chain of single ring can be connected with the - SO3H, - OH, - NH2 and - COOH hydrophilic groups, alkyl, alkoxy substituent such as, or may make the backbone with polyoxyethylene isometric chain groups, so the water reducing agent has a comb structure.
The high efficiency water reducing agent general volume 0.2% ~ 0.5%, has high water reducing rate, concrete slump loss is smaller ( in the side group type suitable cases ) features. In recent years some domestic manufacturers of synthetic production of this type of superplasticizer and put into practical use. Despite its synthesis process is simple, low synthesis temperature ( 80 ~ 110oC ), but because the raw material of p-amino benzene sulfonic acid sodium, such as phenol price rise, this kind of high efficiency water reducing agent production cost is relatively high, which is in high strength and high performance concrete with certain technical advantages, but the application of popularity far as an efficient naphthalene water reducing agent. It is important to note, amino sulfonate superplasticizer higher addition of extremely easy to cause excessive bleeding and coagulation. Therefore, under normal circumstances, amino sulfonate superplasticizer naphthalene superplasticizer compound, it can not only improve the naphthalene efficient superplasticizer with cement adaptability, but also can enhance the concrete slump retention.
( 4) the aliphatic superplasticizer
Aliphatic superplasticizer mainly refers to using acetone, formaldehyde and sulfite, synthesis of aliphatic hydroxy sulfonate condensates ( also known as ketone aldehyde condensation compound ), its structure is characterized by a hydrophobic backbone for aliphatic hydrocarbon, and hydrophilic mainly for the - SO3H, - COOH, - OH.
Aliphatic superplasticizer adequate production of raw materials and cheap, simple process ( 80-100oC synthesis temperature ), so the synthesis of relatively low cost, the high water reducing rate, on concrete plasticizing enhancement effect and naphthalene, melamine superplasticizer close. Do not make concrete excessive bleeding, less influence on the setting time of concrete.
Aliphatic superplasticizer in Beijing and Guangdong two has formed a production scale, in the domestic production and application is not common. The product water reducing rate in concrete, the early degrees ( 3 days) and late strength ( 28 days a year ) development has stimulative effect; winter without crystallization, no air, no chlorine salt, of a rusty steel; the adaptability of cement is superior to that of naphthalene products, suitable for precast concrete production. The product with other admixtures compatibility of components, the compound can be prepared into a series of products, and achieve pumping, delayed coagulation, early strength antifreeze, waterproof, and so on, to meet the various requirements of the commodity concrete.
Aliphatic superplasticizer was red brown, although does not affect the intrinsic properties of concrete, but after doped will make the concrete color red, present in high-strength concrete pipe pile applied in the production of more, and in the naphthalene superplasticizer price rising period, the more favored by the users. Guangdong Ke Jie company production of the KJ series of aliphatic superplasticizer preparation of C80 high strength concrete, fully shows that the products of excellent technical performance.