课程名称︰钢筋混凝土学
课程性质︰土木工程学系必修
课程教师︰欧昱辰
开课学院：工学院
开课系所︰土木工程学系
日期（年月日）︰2018/9/20公布题目～2018/9/27截止
时限（分钟）：一个礼拜，大概是一万分钟
作业一(Homework one)
缴交日期(Due date):9/27
(1)一矩形钢筋混凝土柱断面40cm x 50cm，柱长为100cm，混凝土fc'=280kgf/cm^2，
(a)何谓混凝土之潜变与潜变系数？潜变对钢筋混凝土构件之行为有何影响？
(b)若该柱承受之轴向应力 P = 20tf，是球三年后之总轴向变形，不考虑收缩变
形，且混凝土潜变系数Ct = 2.9。
(c)若柱轴心线上配置一支D32钢筋，且钢筋与混凝土间握裹良好，则钢筋因混凝
土潜变所产生之应力变化为何？
注：
(1)本题合并99、104年高考与94年结构技师考题，再稍加改而成。
(2)本题之Ct为三年后之潜变系数。
(3)设(b)小题没有配置钢筋。
A rectangular reinforced concrete column has a cross sectional dimension of
40cm x 50cm and a height of 100cm, fc' = 280kgf/cm^2,
(a)What is the creep and the creep of coefficient of concrete? What are the
effects of concrete creep on the behavior of reinforced concrete members?
(b)If the column is subjected to an axial load P = 20tf, calculate the total
axial deformation of the column after three years. Neglect the shrinkage
deformation. The creep coefficient Ct = 2.9.
(c)A D32 bar is added along the central longitudinal axis of the column. A
perfect bond is assumed between the ber and concrete. Calculate the change
of the stress in the bar due to concrete creep.
Note:
(1)This question is modified from questions given in the past national exams.
(2)The Ct is the creep coefficient after three years.
(3)Assume no reinforcement used in question(b).
(2)将以下以英制表达(单位：psi,in)的公式转换成以公制表达(kgf/cm^2,cm)
(Ld) = 0.06(Ab)(fy) / (fc')^(0.5) ， Ld：钢筋伸展长度；Ab：钢筋断面积
Convert the following quation from the imperial system (psi and in) to the
metric system(kgf/cm^2, cm)
(Ld) = 0.06(Ab)(fy) / (fc')^(0.5) ， Ld: development length of reinorcement;
Ab: cross sectional area of reinforcement
(3)某预拌混凝土厂提供一批混凝土抗压强度为fc'=350kgf/cm^2的试体强度资料，资料如
下表（平均值=352.5kgf/cm^2，标准差Ss = 10.291kgf/cm^2），求此混凝土配比目标抗
压强度fcr'。（单位：kgf/cm^2）
A ready mix concrete plant provides the following compressive strength data fo
for concrete with fc' = 350kgf/cm^2(mean = 352.5kgf/cm^2; standard deviation
Ss = 10.291kgf/cm^2). Calculate the required average compressive strength of
concrete fcr' for fc' = 350kgf/cm^2.
357 351 360 368 363 356 333 342 340 349
352 341 336 347 353 365 356 362 350 343
351 342 348 339 372 361 363 368 359 348
注(Note)：
本题为100年高考题。
This question is from a 2011 national exam.