摘要
针对北京市场上的砂石质量现状,时有含泥量较高的砂进入搅拌站被应用于生产。对使用聚羧酸高性能减水剂生产的混凝土质量和性能影响更大。因此,对于搅拌站常用强度等级混凝土,通过选取3种不同含泥量的砂子对混凝土进行新拌性能和强度的试验,以验证砂含泥量对掺聚羧酸高效减水剂混凝土性能的影响,并通过采取技术措施和调整配合比满足要求后,对配合比的经济指标分析。结果表明较高的砂含泥量使掺聚羧酸高性能减水剂的混凝土性能下降明显,对混凝土的质量和成本造成巨大影响。由此得出结论:搅拌站应挑选优质砂以满足混凝土质量要求。当生产高强混凝土时,如含泥量超标,则必须停产。使用含泥量高的砂即使经过调整可以生产较低强度等级混凝土,但由于生产成本增加较大,经济效益很差。不如适当提高砂的采购价格,采购质量较好砂子,既能保证质量,经济上也较为合理。试验仅验证了砂含泥量对混凝土和易性和28d强度的影响,目的主要是为指导生产中原材料和混凝土的质量控制。砂中含泥量对混凝土长期性能和耐久性能的影响还需做进一步研究。
According to the current situation of concrete aggregate on Beijing＇s market,sand of high clay content has been using in concrete batching plant for production frequently,which made a significant impact on concrete quality and performance with polycarboxylic high perfor-mance water reducer.This paper validated the effect of clay content of sand on concrete performance with polycarboxylic high performance water reducer through a series of experiments on performance of fresh concrete and its strength which the class often used in batch plant by choosing three different clay content of sand.Furthermore,the paper also carried on a lot of work on concrete mix ratio adjustment and technical improve-ment and made relevant analysis on economic index.The results indicated that along with the increase of clay content,the performance of concrete dramatically reduced,which brought in enormous influence on concrete quality and cost.The conclusion could be like that：concrete batching plant should select high-quality sand to meet the requirements of concrete production,and it must be shut down when high clay content sand was used in high strength concrete production.Although the high clay content sand could be applied in lower strength concrete,the great increase of cost would exert negative effects on its economic benefit.So increasing purchase cost and buying higher-quality sand is economic and reasonable.Experiment re-vealed the effects of clay content on concrete workability and 28 d strength;it will provide some useful suggestion for the quality control of raw mate-rials and concrete.There is still a lot work to do on the influence of clay content on concrete long-term performance and durability in the future.
出处
《混凝土》
CAS
CSCD
北大核心
2011年第2期95-96,112,共3页
Concrete
关键词
砂含泥量
混凝土和易性
强度
配合比比调整
成本分析
clay content
concrete workability
concrete strength
mix ratio adjustment
cost analysis
