肯尼亚天然火山灰质材料对混凝土收缩和徐变性能的影响

通过与粉煤灰对比以及与粉煤灰复掺使用，研究肯尼亚两种天然火山灰质材料对混凝土收缩和徐变性能的影响。结果表明:掺加天然火山灰质材料后混凝土早期强度发展较为缓慢，但28天以后强度增长稳定，84天强度即可与纯水泥混凝土组相当；掺加天然火山灰质材料可减小混凝土收缩和徐变，但收缩率和徐变度均比粉煤灰混凝土大，磨细火山渣与粉煤灰复掺可明显减小天然火山灰混凝土的长期收缩及徐变。

Impact of African Natural Pozzolanic Materials on Concrete Shrinkage and Creep Properties

By comparing with the fly ash and the use of fly ash combined admixture, the impact of Kenya’s two natural pozzolanic materials on concrete shrinkage and creep of are studied. The results show that the addition of natural pozzolanic materials, the concrete strength slowly changes in early period, is stably improved after 28 d, and comparable with the strength of non-additive cement concrete after 84 d; the addition of natural pozzolanic materials can reduce concrete shrinkage and creep, but the ratio of shrinkage and creep is also larger than those of fly ash concrete, fine grinding cinder mixed with fly ash can obviously reduce the long-term shrinkage and creep of natural pozzolanic concrete.