Based on standard test method ASTM C1550 for fibre reinforced concrete (FRC), a modified round panel test method for the material performance of FRC by measuring crack opening width is presented.

在美国材料试验协会标准ASTM C1550圆板试验方法基础上，提出一种改进的基于裂缝宽度量测技术的纤维混凝土(FRC)材料静定圆板试验方法。

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In the first four weeks after its opening, two years ago, 15 people were hurt while viewing Doris Salcedo's Shibboleth, a giant crack cut into the floor of the hall.

两年前，在开幕后的头四个星期内，多丽丝·赛尔萨埵（Doris Salcedo）表演《口令》时厅里的地板上裂了个大口子，造成15个观众受伤。

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The sun's magnetic field near Earth has tipped south, opening a crack in Earth's magnetic defenses against the solar wind.

太阳在地球附近的电磁场已经偏向南方，在地球抵御太阳风的磁场防卫层上打开了一道口子。

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So the first, smaller or easier action (opening the door a crack) makes the second, larger or more difficult action more likely.

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Nalbandian has slipped to 25th in the rankings this season, but after his shaky start in the opening set he became the first player to crack the Federer serve during the tournament.

BBC: Nalbandian beats Federer in Spain

Mr. LARRY NOBEL (Former General Counsel, Federal Election Commission): If somebody sees a crack in the door, it's hard to stop them from opening it up.

NPR: Primary Jostling Complicates Campaign Cash Rules