課程名稱︰鋼筋混凝土學
課程性質︰土木工程學系必修
課程教師︰歐昱辰
開課學院：工學院
開課系所︰土木工程學系
日期（年月日）︰2018/9/20公布題目～2018/9/27截止
時限（分鐘）：一個禮拜，大概是一萬分鐘
作業一(Homework one)
繳交日期(Due date):9/27
(1)一矩形鋼筋混凝土柱斷面40cm x 50cm，柱長為100cm，混凝土fc'=280kgf/cm^2，
(a)何謂混凝土之潛變與潛變係數？潛變對鋼筋混凝土構件之行為有何影響？
(b)若該柱承受之軸向應力 P = 20tf，是球三年後之總軸向變形，不考慮收縮變
形，且混凝土潛變係數Ct = 2.9。
(c)若柱軸心線上配置一支D32鋼筋，且鋼筋與混凝土間握裹良好，則鋼筋因混凝
土潛變所產生之應力變化為何？
註：
(1)本題合併99、104年高考與94年結構技師考題，再稍加改而成。
(2)本題之Ct為三年後之潛變係數。
(3)設(b)小題沒有配置鋼筋。
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)將以下以英制表達(單位：psi,in)的公式轉換成以公制表達(kgf/cm^2,cm)
(Ld) = 0.06(Ab)(fy) / (fc')^(0.5) ， Ld：鋼筋伸展長度；Ab：鋼筋斷面積
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)某預拌混凝土廠提供一批混凝土抗壓強度為fc'=350kgf/cm^2的試體強度資料，資料如
下表（平均值=352.5kgf/cm^2，標準差Ss = 10.291kgf/cm^2），求此混凝土配比目標抗
壓強度fcr'。（單位：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
註(Note)：
本題為100年高考題。
This question is from a 2011 national exam.