论文部分内容阅读
为获取粗骨料粒径对混凝土材料弯拉强度及尺寸效应的影响,完成27组素混凝土梁四点弯曲试验,获得粗骨料最大粒径10、20、30 mm,尺寸为100 mm×100 mm×400 mm、150 mm×150 mm×550 mm、200 mm×200 mm×700 mm混凝土试件的弯拉强度,采用Bazant尺寸效应理论对试验数据进行分析,提出指数型弯拉强度尺寸效应经验公式.研究结果表明:相同骨料体积率、水灰比和构件尺寸下,混凝土材料弯拉强度随着骨料粒径的增大而降低;各骨料粒径下混凝土弯拉强度均存在尺寸效应现象,小尺寸时尺寸效应现象更显著,骨料粒径30 mm时,混凝土弯拉强度随几何尺寸增大而降低趋势最平缓;Bazant尺寸效应率与试验结果吻合较好,但不适用于全尺寸范围,提出的指数型尺寸效应经验公式,在全尺寸范围内能够较好地反映混凝土弯拉强度,可用于混凝土材料弯拉强度尺寸效应预测.
In order to obtain the effect of coarse aggregate size on the bending strength and size effect of concrete, the four-point bending test of 27 concrete plain concrete beams was finished. The maximum aggregate size of coarse aggregate was 10, 20 and 30 mm and the size was 100 mm × 100 mm × 400 mm, 150 mm × 150 mm × 550 mm, 200 mm × 200 mm × 700 mm, the Bazant size effect theory was used to analyze the test data, and the experiential experience of exponential flexural strength was proposed The results show that the flexural strength of concrete decreases with the increase of the aggregate size under the same aggregate volume fraction, water-cement ratio and component size. The flexural strength of concrete under each aggregate size exists When the aggregate size is 30 mm, the bending strength of concrete tends to decrease with the increase of geometric size. The Bazant size effect rate is in good agreement with the experimental results, but not suitable for Full-size range, exponential dimensional effect of the proposed empirical formula, the full size range can better reflect the flexural strength of concrete, flexural strength can be used for the prediction of the size effect of concrete materials.