辉绿岩人工砂石粉的研究与利用

通过对辉绿岩母岩、辉绿岩人工砂石粉、辉绿岩石粉胶砂性能及其水化产物的试验研究,提出辉绿岩人工砂级配连续性较差,石粉含量大,石粉中微粉颗粒多的原因主要是辉绿岩母岩硬度高、性脆所致,并与母岩矿物中的蚀变物有关.辉绿岩人工砂石粉对碾压混凝土的需水量,凝结时间等工作性能的影响,主要基于石粉浸润吸水和其粗糙的多角形颗粒对试验时测针下沉时的摩阻力.此外,还包括微石粉对水泥早期水化过程的影响.辉绿岩石粉颗粒在胶砂中的作用是微集料填充,其中的微粉颗粒在水化硅酸钙凝胶延伸搭接过程中还起支点作用,对胶砂的长龄期强度无不良影响.在此基础上提出用部分微石粉等量替代粉煤灰等措施,解决了辉绿岩人工骨料碾压混凝土施工难题,成功地应用于地处亚热带地区百色大坝工程高强度施工.

Research on artificial dlabase aggregate and powder and utilization

Experimental studies on properties of the parent rock of diabase,the rock powder of artificial diabase sand and the cemented sand and powder of diabase rock powder as well as their hydration products show that the reasons for poor gradation continuity of artificial diabase sand,large rock powder content in this sand,and much micro particles in this rock powder are mainly in the high hardness,brittleness of diabase parent rock,and are related to the alternation products in minerals of the parent rock.The influence of the rock powder in artificial diabase sand on the water demand,setting time,etc.of RCC is mainly based on the water obsorption of the rock powder and on the friction resistance of its rough multiangular grains against the settlement of the point gauge during test.In addition,the micro particles of rock powder also have influence on the early cement hydration process,the grains of diabase powder in cemented sand act as micro aggregate filler and their micro particles also act as supporting points in the extending and lapping process of the gel of calcium silicate hydrate,with no adverse impact on the long-term strength of the cemented sand.Some technical measures are put forward,such as a portion of micro rock powder being substituted for equivalent flyash,resolving difficult technical problems in the construction of RCC of artificial diabase aggregate and successfully applying this technology in the high-intensity construction of Baise dam in the subtropic zone.