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كارشناسي ارشد

مكانيك - تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1393

سيزده،76ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

علي اكبر عالم رجبي

احمد صابونچي

5/11/93

محمدرضا سليم پور، محمود اشرفي زاده

مهندسي مكانيك

ID8790

چكيده بان خودماراكم به عنوان يكي از بانهي فوق توانمند به دليل هكلپذير و پييدار در برابر جداهدگي و عدم نييز به عملييت ويبره در سيز در صنيت سيخامين محققين را برآن داهت تي بي حين اجرا از اهميت بساايي برخوردار ميبيهد همچنين توجه به بحث سب به كيهش وزن اين بانهي بپردازند در اين پژوهش به بررسي خواص حرارتي در كنير خواص اساسيده از مصيلح و سنزدانههي سب و زئوليت خودماراكم پرداخاه هده است و تيثير افاودن فوق روانكننده جييزايني پوزوالنهي ميكروسيلي مكينيكي بانهي سب به جي سيمين پرتلند در درصدهي 21 51 و 22 و در ناييت تيثيرجييزايني دانههي ليكي پوكه ميدني و پرليت به جي دانههي هن و ميسه ميمولي در بان مورد بررسي قرار گرفت نسبت آر به سيمين در كليه طرح هي برابر بي 54 2 در نظر گرفاه هد از آن جات ميده مصرفي ميبيهد در طرحهي اخاالطجييزاين هيچ ميده ا نميهود و صرفي در مقييسه بي سيمين نسبت به كه فوقروانكننده ي كيرايي بان از 5 2 تي 5 1 مورد اساسيده قرار گرفت در اين پژوهش به منظور محيسبه ضريب هدايت حرارتي اين بانهي دسازيه صسحه داغ محيفظت هده كه در اسايندارد 771 ASTM C توصيه هده است مورد اساسيده قرار گرفت چزيلي بانهي از تقسيم جرم بر حجم بانهكن ديجيايلي اساسيده هد طبق ناييج بدست آمده در بين آناي محيسبه هد به منظور محيسبه مقيومت فشير از دسازيه ج بود 27 بيشار از بان نمونههي مورد بررسي بيشارين مقيومت فشير مربوط به نمونه بان خودماراكم حيو 21 ميكروسيلي خودماراكم حيو ليكي دانه بند 22 پرليت و ميمولي كمارين ضريب هدايت حرارتي و كمارين چزيلي مربوط به نمونه بان سب بود 13 كيهش برا ضريب هدايت حرارتي و 45 كيهش برا چزيلي 21 پوزوالن ميكروسيلي كلميت كليد 1 دسازيه صسحه داغ محيفظت هده 2 ضريب هدايت حرارتي 3 مقيومت فشير 4 بان ساب خودماراكم 5 ليكي 1 پوكه ميدني 7 پرليت

14Thermal Conductivity Investigation of Lightweight Self Compacting Concretes Mohammad Reza Daneshgar Daneshgar heat@yahoo com Date of Submission 20 10 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Language Farsi Degree M Sc Supervisor Ali Akbar Alemrajabi rajabi@cc iut ac ir Abstract Concrete is the most common building material with a high thermal mass and it is of interest to study how thermal mass of buildings influences such factors as their peak power consumption and their thermal comfort Lightweight concretes can be produced by using processed natural materials processed by products or unprocessed porous materials depending upon the requirements of density and strength levels In this study the thermal conductivity density and compression strength of some novel lightweight self compacting concretes LSCC were investigated Thermal conductivity is the property of a material related to heat conduction It is evaluated primarily by applying Fourier s Law for heat conduction Heat transfer across materials of high thermal conductivity occurs at a higher rate than across materials of low thermal conductivity Correspondingly materials of high thermal conductivity are widely used in heat sink applications and materials of low thermal conductivity are used as thermal insulation The standard ASTM C177 specifies the test procedure for laboratory measurement of the steady state heat flux through flat homogenous specimens with their specimens in contact with solid parallel boundaries held at constant temperature using the guarded hot plate This method was used to determine the thermal conductivity of concrete specimens Poly carboxylate Super plasticizers is a highly flow able and non segregating concrete additive Self compacting concrete SCC has an ability to flow through congested reinforcements efficiently irrespective of the structure geometry In the test specimens the water cement ratio was 0 45 and between 0 50wt to 1 5wt Super plasticizers was added to gain an acceptable workability In this study sand has been replaced by non aggregated and aggregated LECA pumice and perlite Zeolite and micro silica has been used as partial replacement of Portland cement at ratios of 10 15 and 20 Results indicated that this lightweight SCCs by zeolite or micro silica was not only lighter but had higher compressive strength and lower thermal conductivity in comparison to conventional concrete Zeolite and micro silica tend to increase compression strength up to 68 and thermal conductivity 1 45 at 10wt Super plasticizers provide a network of covalent coupling among the micro silica and zeolite with LECA particles This network increases the compressive strength But when zeolite and micro silica content were higher than 10 compression strength decreased Using non aggregated and aggregated LECA instead of silica aggregates in SCC can reduce concrete density up to 30 Non aggregated LECA reduces the thermal conductivity more effectively than LECA aggregates The reason being that coarse LECA aggregates have more porosity and the coefficient of thermal conductivity is significantly reduced reduction for non aggregated LECA is approximately 28 and for aggregated LECA is 17 Density of concrete depends on its components Compressive strength of concrete containing non aggregated LECA is approximately 20 lower than concrete containing aggregated LECA This is due to the fact that strength of concrete is proportional to its density Compared to conventional concrete pumice concrete is approximately six times lighter Thermal conductivity and compressive strength of concrete containing pumice was almost the same as aggregated LECA concrete Perlite is a volcanic rock with acidic to intermediate composition which forms in the wet condition or aqueous environment Perlite tends to decrease compression strength thermal conductivity and density of concrete When 10 micro silica 20 perlite and LECA aggregates were used t

علي اكبر عالم رجبي

احمد صابونچي

محمدرضا سليم پور، محمود اشرفي زاده