砂粒实验

1、砂的颗粒级配区:
天然砂颗粒级配区
&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp级配区
累计筛余(%)

筛孔尺寸(mm)&nbsp&nbsp&nbsp&nbspⅠ&nbsp区&nbspⅡ&nbsp区&nbspⅢ&nbsp区
10.0&nbsp0&nbsp0&nbsp0
5.00&nbsp10~0&nbsp10~0&nbsp10~0
2.50&nbsp35~5&nbsp25~0&nbsp15~0
1.25&nbsp65~35&nbsp50~10&nbsp25~0
0.630&nbsp85~71&nbsp70~41&nbsp40~16
0.315&nbsp95~80&nbsp92~70&nbsp85~55
0.160&nbsp100~90&nbsp100~90&nbsp100~90
注:砂的实际颗粒级配应与上表所列累计筛余百分率相比,除5.00mm和0.630mm筛档外,其余可稍超出界限,但其总量百分率不应大于5%。
2、砂的粗细程度:
名称&nbsp细度模数&nbsp名称&nbsp细度模数
粗砂&nbsp3.7~3.1&nbsp中砂&nbsp3.0~2.3
细砂&nbsp2.2~1.6&nbsp特细砂&nbsp1.5~0.7
3、天然砂的坚固性指标评定:采用硫酸钠溶液检验,式样在硫酸钠饱和溶液中经五次循环浸渍后的重量损失率应符合下表规定:

混凝土所处的环境条件&nbsp经五次循环后的重量损失(%)
最冷月平均气温低于0℃的地区,并经常处于潮湿或干湿交替状态下的混凝土。&nbsp
<8
其他条件下使用的混凝土&nbsp<10
4、天然砂中有害物质含量:

<C30&nbspC30~C50&nbspC55~C60
含泥量
(按重量计,%)&nbsp≤5.0&nbsp≤3.0&nbsp<
泥块含量
(按重量计,%)&nbsp<1.0&nbsp<0.5&nbsp<0.5
硫化物及硫酸盐含量(折算成SO3,(按重量计,%)&nbsp<1.0&nbsp<1.0&nbsp<0.5
云母含量((按重量计,%)&nbsp≤1.0&nbsp≤1.0&nbsp<0.5
轻物质(比重小于2,如煤、贝壳等)含量(按重量计,%)&nbsp≤1.0&nbsp≤1.0&nbsp≤1.0
有机物含量(用比色法实验)&nbsp颜色不能深于标准色。当深于标准色时,则应按水泥胶砂强度检验方法进行强度对比实验,抗压强度比不应低于0.95。
注:1、泥块系指砂中粒径大于1.25mm的颗粒,经水洗、水捏后变成小于0.630mm的颗粒;
2、对有抗冻、抗渗或其他特殊要求的混凝土用砂,含泥量不大于3%;
3、当砂中发现有颗粒状的硫酸盐或硫化物杂质时,应进行专门检验,仅在确认满足混凝土耐久性要求时,方可使用。

5、粗骨料颗粒级配范围:



况&nbsp累计筛余(%)&nbsp&nbsp&nbsp&nbsp&nbsp筛孔尺寸(mm)

公称粒径(mm)&nbsp2.50&nbsp5.00&nbsp10.0&nbsp16.0&nbsp20.0&nbsp25.0&nbsp31.5&nbsp40.0&nbsp50.0&nbsp63.0&nbsp80.0&nbsp100




径&nbsp5~10&nbsp95~100&nbsp80~100&nbsp0~15&nbsp0&nbsp——&nbsp——&nbsp——&nbsp——&nbsp——&nbsp——&nbsp——&nbsp—
&nbsp5~16&nbsp95~100&nbsp90~100&nbsp30~60&nbsp0~10&nbsp0&nbsp——&nbsp——&nbsp——&nbsp——&nbsp——&nbsp——&nbsp—
&nbsp5~20&nbsp95~100&nbsp90~100&nbsp40~70&nbsp——&nbsp0~10&nbsp0&nbsp——&nbsp——&nbsp——&nbsp——&nbsp——&nbsp—
&nbsp5~25&nbsp95~100&nbsp90~100&nbsp——&nbsp30~70&nbsp——&nbsp0~5&nbsp0&nbsp——&nbsp——&nbsp——&nbsp——&nbsp—
&nbsp5~31.5&nbsp95~100&nbsp90~100&nbsp70~90&nbsp——&nbsp15~45&nbsp——&nbsp0~5&nbsp0&nbsp——&nbsp——&nbsp——&nbsp—
&nbsp5~40&nbsp——&nbsp95~100&nbsp75~90&nbsp——&nbsp30~60&nbsp——&nbsp——&nbsp0~5&nbsp0&nbsp——&nbsp——&nbsp—
&nbsp5~63&nbsp95~100&nbsp95~100&nbsp85~95&nbsp60~80&nbsp45~70&nbsp——&nbsp30~40&nbsp15~20&nbsp——&nbsp0~5&nbsp0&nbsp—
&nbsp5~80&nbsp95~100&nbsp95~100&nbsp80~95&nbsp——&nbsp60~80&nbsp——&nbsp——&nbsp30~60&nbsp——&nbsp15~20&nbsp0~5&nbsp0

6、粗骨料压碎指标:
混凝土强度等级&nbsp≥C30&nbsp<C30
压碎指标&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp岩石种类
(按重量损失计,%)

粗骨料种类&nbsp沉积岩&nbsp深成岩
变质岩&nbsp喷出岩&nbsp沉积岩&nbsp深成岩
变质岩&nbsp喷出岩
碎&nbsp&nbsp&nbsp石&nbsp≤10&nbsp≤12&nbsp≤13&nbsp≤13&nbsp≤20&nbsp≤30
卵&nbsp&nbsp&nbsp石&nbsp≤9&nbsp≤12&nbsp—&nbsp≤12&nbsp≤16&nbsp—
7、粗骨料坚固性指标:
经五次循环后的重量&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp结构或构件
&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp损失率(%)&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp类型
混凝土所处的环境条件&nbsp混凝土结构&nbsp预应力混凝土结构
最冷月平均气温低于0℃的地区,并经常处于潮湿或干湿交替状态下的混凝土&nbsp≤8&nbsp≤5
其他条件下使用的混凝土&nbsp≤12&nbsp≤8
注:1、当粗骨料未达到本表规定的坚固性指标,但混凝土经实验具有足够的抗冻性时,也可采用;
&nbsp&nbsp&nbsp&nbsp2、对粗骨料的吸水率小于0.5%时,可不作坚固性实验;
&nbsp&nbsp7、粗骨料中有害物质含量:
&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp混凝土
含&nbsp量&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp强度等级
项&nbsp&nbsp&nbsp目&nbsp&nbsp≥C30&nbsp<C30
针、片状颗粒总含量(按重量计,%)&nbsp≤10&nbsp≤10
含泥量(按重量计,%)&nbsp≤1.0&nbsp≤2.0
泥块含量(按重量计,%)&nbsp≤0.25
硫化物及硫酸盐含量(折算成SO3,按重量计,%)&nbsp≤1.0&nbsp≤1.0
氯化物(以Nacl计,%)&nbsp0.03&nbsp—
卵石中有机物含量(用比色法试验)&nbsp颜色不应深于标准色。当深于标准色时,应配置成混凝土进行对比试验,抗压强度比不应低于0.95

8、混凝土最大水灰比和最小水泥用量:
混凝土所处的环境条件&nbsp所在地区最冷平均气温
&nbsp低于–15&nbsp–15~–15&nbsp高于–15
&nbsp最大水灰比&nbsp最小水泥用量(kg/m3)&nbsp最大水灰比&nbsp最小水泥用量(kg/m3)&nbsp最大水灰比&nbsp最小水泥用量(kg/m3)
受水流冲刷、冰冻作用的混凝土&nbsp0.55&nbsp300&nbsp0.60&nbsp275&nbsp0.65&nbsp250
最低冲刷线以下的底下部分,不受水流作用的地上部分及不致遭受冰冻作用的混凝土&nbsp0.60&nbsp275&nbsp0.65&nbsp250&nbsp0.70&nbsp230

9、混凝土塌落度
结构类型&nbsp蹋落度(mm)
无配筋或配筋稀疏的混凝土(基础、墩台、隧道衬砌、挡土墙等)&nbsp30~50
普通配筋率的钢筋混凝土结构(板、梁、柱等)&nbsp50~70
配筋较密的钢筋混凝土结构(墙、梁、柱等)&nbsp70~90
配筋较密不便捣实的钢筋混凝土结构&nbsp100~140

10、混凝土的用水量:
&nbsp粗骨料品种规格
&nbsp&nbsp

落度(mm)&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp卵石最大粒径(mm)&nbsp碎石最大粒径(mm)
&nbsp10&nbsp20&nbsp25&nbsp31.5&nbsp40&nbsp63&nbsp80&nbsp16&nbsp20&nbsp25&nbsp31.5&nbsp40&nbsp63&nbsp80
10~30&nbsp190&nbsp170&nbsp170&nbsp160&nbsp150&nbsp145&nbsp140&nbsp200&nbsp185&nbsp185&nbsp175&nbsp165&nbsp155&nbsp150
35~50&nbsp200&nbsp180&nbsp180&nbsp170&nbsp160&nbsp155&nbsp150&nbsp210&nbsp195&nbsp195&nbsp185&nbsp175&nbsp165&nbsp160
55~70&nbsp210&nbsp190&nbsp190&nbsp180&nbsp170&nbsp165&nbsp160&nbsp220&nbsp205&nbsp205&nbsp195&nbsp185&nbsp175&nbsp170
75~90&nbsp215&nbsp195&nbsp195&nbsp185&nbsp175&nbsp170&nbsp165&nbsp230&nbsp215&nbsp215&nbsp205&nbsp195&nbsp185&nbsp180

11、混凝土砂率:
&nbsp&nbsp&nbsp&nbsp粗骨料品种
规格
水灰比&nbsp卵石最大粒径(mm)&nbsp碎石最大粒径(mm)
&nbsp10&nbsp20&nbsp30&nbsp40&nbsp63&nbsp80&nbsp16&nbsp20&nbsp25&nbsp40&nbsp63&nbsp80
0.40&nbsp27~32&nbsp26~31&nbsp25~30&nbsp24~39&nbsp23~28&nbsp22~27&nbsp31~36&nbsp30~35&nbsp29~34&nbsp28~33&nbsp27~32&nbsp25~30
0.50&nbsp31~36&nbsp30~35&nbsp29~34&nbsp28~33&nbsp27~32&nbsp26~31&nbsp33~38&nbsp32~37&nbsp31~36&nbsp30~35&nbsp29~34&nbsp28~31
0.60&nbsp34~39&nbsp33~39&nbsp32~37&nbsp31~36&nbsp30~35&nbsp29~34&nbsp36~41&nbsp35~40&nbsp34~39&nbsp33~38&nbsp32~37&nbsp31~36
0.70&nbsp37~42&nbsp36~41&nbsp35~40&nbsp34~39&nbsp33~38&nbsp32~37&nbsp39~44&nbsp38~43&nbsp37~42&nbsp36~41&nbsp35~40&nbsp34~39

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