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c20c30c40混凝土配合比设计计算步骤 [复制链接]

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c20c30c40混凝土配合比设计计算步骤ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

C20混凝土配合比初步计算ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
设计步骤:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(一)设计初步配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、确定混凝土配制强度fcu,o=1.645×5+20=28.2MPaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、计算水灰比(w/cÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
w/c=aa×fce/fcu,o+ aa×ab×fceÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
=0.46×32.5×1.13/28.2+0.46×0.07×32.5×1.13ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
=0.57ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
3、选定单位用水量(MwoÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
由于碎石最大粒径31.5mm,选用混凝土用水量:Mwo=180Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
4、计算单位用灰量(McoÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1)按强度计算单位用灰量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
Mco= Mwo/ w/c=180/0.57=316Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
5、选择砂率(βsÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
胜根据碎石最大粒径31.5mm及水灰比w/c=0.57,选定混凝土砂率取βs=34%ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
6、计算砂石用量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1)采用质量法ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
已知:单位用灰量Mwo=180 Kg/m3,砂率βs=34%ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
Mso+Mgo=PcpMcoMwoÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
Mso/Mso+Mgo=0.34ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
假设混凝土混合料湿表观密度Pcp=2400 Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
Mso+Mgo=2400-316-180ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
Mso/Mso+Mgo=0.34ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
解得砂用量Mso=647Kg/m3,碎石用量Mgo=1257Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
Mco : Mwo : Mso : Mgo =316: 180 : 647 : 1257ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1 : 0.57 : 2.05 : 3.98 w/c=0.57ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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2#

回复:c20c30c40混凝土配合比设计计算步骤

原始资料:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、混凝土设计强度等级为C30(空心板)无强度历史统计资料,桥梁所在地区属寒区。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、组成材料:PO42.5等级牡丹江牌水泥,密度PC=3.1×103Kg/m3,富裕系数=1.13,砂为中砂表观密度P'S=2.65×103Kg/m3,碎石最大粒径dmax=40mm,表观密度P'g=2.75×103Kg/m3,水为一般饮用水。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
设计步骤:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(一)设计初步配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、确定混凝土配制强度(Ryp=Ry+1.65б=30+1.645×5=38.2MPaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、计算水灰比(w/c)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(1)按强度要求计算水灰比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
           Rs=RCRb=1.13×42.5=48MPaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(2)计算混凝土水灰比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
w/c=ARs/Ryp+ABRs=0.48×48/38.2+0.48×0.52×48=23/50.1=0.46ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(3)按耐久性校核水灰比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
    根据混凝土所处环境属于寒区允许最大水灰比为0.55.按强度计算水灰比是0.46。符合耐久性要求,采用计算水灰比0.46。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
3、选定单位用不水量(Mwo)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
   由于碎石最大粒径40mm,选用混凝土用水量:Mwo=175Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
4、计算单位用灰量(Mco)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(1)按强度计算单位用灰量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
      Mco= Mwo/ w/c=175/0.46=380 Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(2)按耐久性校核单位用灰量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据混凝土所处环境属寒区配筋混凝土,最小水泥用量不低于300 Kg/m3,按强度计算单位用灰量380 Kg/m3,符合耐久性要求,采用单位用灰量为380 Kg/m3。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
5、选择砂率(βs)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
胜根据碎石最大粒径40    mm及水灰比w/c=0.46,选定混凝土砂率取βs=32%。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
6、计算砂石用量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(1)采用质量法ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
已知:单位用灰量Mwo=175 Kg/m3,砂率βs=33%ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
      Mso+Mgo=Pcp-Mco-MwoÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
      Mso/Mso+Mgo=0.33ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
假设混凝土混合料湿表观密度Pcp=2400 Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
     Mso+Mgo=2400-380-175ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
     Mso/Mso+Mgo=0.33ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
解得砂用量Mso=609 Kg/m3,碎石用量Mgo=1236 Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
按质量法计算初步配合比:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
     Mco : Mwo : Mso : Mgo =380 : 175 : 609 : 1236ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
即:  1 : 0.46 : 1.6 : 3.25 w/c=0.46ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(二)试拌混凝土,提出基准配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、按计算初步配合比试拌15L混凝土拌后物,测定其坍落度为2.5cm,满足施工和易性要求,其粘聚性和保水性亦良好。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、提出基准配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
   Mca :Msa :Mga=1 :1.6 : 3.25, w/c=0.46ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(三)检验强度,测定试验室配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、检验强度ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
采用水灰比分别为(w/c)A=0.41  B=0.46  C=0.51拌制三组混凝土拌和物。砂、碎石用量不变,用水量亦保持不变。三组配合比经拌制成型,在标准条件养护28d后,A组抗压强度为41.5MPa,B组抗压强度为34.0MPa,C组抗压强度为28.5MPa。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
绘制混凝土配制强度Ryp=38.2MPa的灰水比c/w2.38关系曲线即水灰比w/c=0.42ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、确定试验室配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
        Msb+Mgb=2400-417-175ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
        Msb/ Msb+ Mgb=0.33ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
即Msb=596,Mgb=1213ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
修正后配合比Mcb:Msb:Mgb=417:596:1213=1:1.43:2.91ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水灰比Mwb/Mcb=175/417=0.42ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
计算湿表观密度Pcp=417+175+596+1213=2401 Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
实测湿表观密度P'cp=2400 Kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
修正系数б=2400/2401=1ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
因此试验室配合比为Mcb':Msb':Mgb'=1:1.43:2.91, w/c=0.42ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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3#

回复: c20c30c40混凝土配合比设计计算步骤

C40混凝土配合比设计ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

C40混凝土用于某公路K**+***桥钢筋混凝土施工,要求施工时现场坍落度为30~50mm,碎石的最大粒经为30mm。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
材料选择ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水泥:采用牡丹江产P.O42.5普通硅酸盐水泥。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
砂:产地岔林河,细度模数2.62属于中砂,颗粒级配属 Ⅱ区。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
碎石:产地冷山,规格分别为16~31.5cm、4.75~16cm,压碎值、含泥量等指标也均符合规范求。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
粗集料配合比设计ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据筛分结果粗集料的掺配比例为: 4.75~16cm cm碎石为35%ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
16~31.5cm cm碎石为65%。
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
  按照上述比例掺配两种集料,经几次筛分试验,其结果均满足4.75~31.5cm碎石连续级配.ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
配合比设计ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、计算初步配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1)确定混凝土配制强度(fcu,o)。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
混凝土设计强度fcu,k=40MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
标准差σ=5.0 Mpa
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
则混凝土配制强度:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
fcu,o= fcu,k+1.645×σ=48.2 MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2)计算水灰比(W/C)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(1)按强度要求计算水灰比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
①计算水泥实际强度ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
采用42.5普通硅酸盐水泥fce,k=42.5Mpa,富余系数γc=1.13ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
则水泥实际强度为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
fce=fce,k
×γc =48.0MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
计算水灰比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
碎石 A=0.48ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
B=0.52
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
W/C=A×fce/(fcu,o+A ×B ×f ce)=0.45ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(2)按耐久性校核水灰比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据桥梁施工规范要求:严寒地区受严重冰冻,水流侵蚀最大水灰比不得大于0.65。按照强度计算的水灰比符合耐久性要求,故采用0.45。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(3)确定单位用水量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据要求,混凝土拌和物的坍落度为30~50mm,碎石的最大粒径为30mm。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
确定混凝土的单位用水量为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mwo=185kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(4)计算单位水泥用量(mco)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
①按强度计算单位用灰量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
已知混凝土单位用水量为ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mwo=185kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水灰比W/C=0.45
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
则计算单位混凝土用灰量:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mco=mwo×c/w=411kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
②按耐久性校核单位用灰量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据桥梁施工技术规范要求:严寒地区受严重冰冻,水流侵蚀作用且有钢筋,混凝土最小水泥用量为300 kg/m3 。按强度计算的单位用灰符合耐久性要求,故采用mco=411kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(5) 确定砂率(SP)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据碎石的最大粒径为30mm,且水灰比为0.45 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
选定混凝土砂率为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
SP=33%ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(6)计算粗,细集料单位用量(mgo , mso)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
假定混凝土毛体积密度为2400 kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
185+411+ mgo+ mso=2400 ¨¨¨¨¨①ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mso×100/(mso+mgo) =33%¨¨¨¨¨②ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
解式①、②得:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mso=595 kg/m3
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mgo=1209kg/m3
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
则混凝土初步配合比为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mco: mso: mgo=1:1.45:2.94
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
W/C=0.45
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、试拌调整,提出基准配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1)计算试拌材料用量ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
按计算初步配合比试拌15L混凝土拌和物,各种材料用量:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水泥:411×0.015=6.165kgÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水:185×0.015=2.775kgÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
砂:595×0.015=8.925kgÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
碎石: 1209×0.015=18.135kgÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2)调整工作性,提出基准配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
按照计算材料用量拌制混凝土拌和物,测定其坍落度为40mm,而且拌和物的粘和性和饱水ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
性良好,满足施工和易性要求,因此提出基准配合比为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mco: mso: mgo=1:1.45:2.94 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
W/C=0.45ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
3、检验强度ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
  1)、采用水灰比分别为0.43,0.45,0.47 拌制三组混凝土拌和物,拌制时用水量不变,水泥用量分别为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
430 kg/m3 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
411 kg/m3 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
394 kg/m3
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2 8
天后抗压强度分别见下表:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水灰比:0.43ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
试件编号

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

1ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

23456
抗压强度

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

51.5ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

52.0ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

52.1ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

53.5ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

52.6ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

51.8ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

平均值

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

52.3MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水灰比:0.45ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
试件编号

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

1ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

23456
抗压强度

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

49.2ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

49.5ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

47.9ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

48.5ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

48.3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

47.2ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

平均值

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

48.4MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水灰比:0.47ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
试件编号

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

1ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

23456
抗压强度

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

45.3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

43.2ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

45.5ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

44.7ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

43.8ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

44.2ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

平均值

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

44.5MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j

ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
  2)、绘制灰水比和强度曲线:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
强度(Mpa)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
灰水比    ( 略 )ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
由混凝土强度与灰水比关系曲线关系可知,与试配混凝土强度38.2Mpa的灰水比值为2.22即水灰比为0.45。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
4、确定试验室配合比ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1)强度修正ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据强度、灰水比关系曲线,按强度修正后混凝土各材料用量为:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
用水量mwb=185kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水泥用量 mcb =411kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
砂用量msb =595kg/m3 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
碎石用量 mgb =1209kg/m3 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
实测混凝土拌和物的毛体积密度为ρh=2470kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
校正系数K=2470/2400=1.03ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
修正后混凝土各材料用量为ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水185×1.03=190kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水泥411×1.03=423kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
砂595×1.03=612kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
碎石1209×1.03=1244kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
则试验室配合比为mcbsbgb=1:1.45:2.94ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
W/C=0.45ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
根据试验室配合比拌制12组抗压试件,标准养护28天后抗压强度见下表:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
试件编号123456
抗压强度ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(Mpa)
48.549.248.749.247.945.9
试件编号789101112
抗压强度ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(Mpa)
48.948.051.752.449.248.7
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2)
、强度评定ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
1、计算实测强度的平均值(mfcu)及标准差(sfcu)ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
标准差sfcu=1.68ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
平均值mfcu=49.0MpaÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
2、根据试件组数(N=12)判定合格系数ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
λ1=1.70 ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
λ2=0.9
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
3
、强度评定ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(1)mfcu-λ1sfcu≥0.9fcu.kÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
49.0-1.7×1.68=46.1Mpa>0.9×40=36.0Mpa   合格ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
(2)fcu.min≥λ2fcu.kÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
45.9Mpa≥0.9×40=36.0Mpa   合格ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
故该12组混凝土试件块强度评定合格ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
上述式中:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
sfcu
————混凝土强度标准差ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mfcu————混凝土强度平均值ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
fcu.k————混凝土设计强度值ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
fcu.min————混凝土强度的最小值ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
λ1 . λ2————评定合格系数.查表得出ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
5
、结论:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
经过理论推算和试验室结果,确定最终配合比:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
mcbsbgb=1:1.45:2.94ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
W/C=0.45ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
每立米混凝土各材料用量:ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水192kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
水泥 423kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
砂612kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
碎石1244kg/m3ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
最后编辑3c3t 最后编辑于 2008-07-21 22:54:42
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4#

回复: c20c30c40混凝土配合比设计计算步骤

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ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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5#

回复:c20c30c40混凝土配合比设计计算步骤

非常感谢ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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回复:c20c30c40混凝土配合比设计计算步骤

好用。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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不错。我收藏了。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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谢谢!我收藏了。ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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非常感谢ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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好东西!ÃMDqy^٘gbbs.3c3t.comÑvíMñ/‰`j
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