簡(jiǎn)述K30試驗(yàn)時(shí)場(chǎng)地和環(huán)境條件的要求、荷載板墊砂的要求,并分析其對(duì)試驗(yàn)結(jié)果的影響?根據(jù)千斤頂校驗(yàn)結(jié)果(見(jiàn)下表)計(jì)算:當(dāng)荷載板的荷載為0.28MPa時(shí),相應(yīng)的油壓應(yīng)當(dāng)加壓到多少M(fèi)Pa?(荷載板直徑30cm,油缸直徑為2.1cm)
已知一攪拌站生產(chǎn)了一批C35混凝土,強(qiáng)度分別為35.0MPa,39.8MPa,42.8MPa,44.8MPa,34.9MPa,37.6MPa,38.8MPa,40.8MPa,41.4MPa,45.5MPa,44.8MPa,該組混凝土強(qiáng)度標(biāo)準(zhǔn)差為3.76 MPa,試對(duì)其進(jìn)行評(píng)定。