高节竹和水泥混合物的水化特性

Hydration characteristics of Phyllostachys prominens wood-cement-water mixtures

考察高节竹作为水泥刨花板生产原料的可行性。按一定质量比调制高节竹粉与水泥和水的混合物 ,并用自制测温装置测定混合物的水化温度时间曲线。在此基础上计算出高节竹的阻凝系数与适合系数 ,以评判高节竹与水泥的相适性。结果表明 :①高节竹的阻凝系数对2种水泥均为∞ ;适合系数对 42 5号水泥为 2 3 % ,对 5 2 5号水泥为 2 8%。②高节竹粉添加Na2 SiO3,NaCl,BaCl2 和CaCl2 后 ,对 42 5号水泥的阻凝系数分别为∞ ,2 5 9 0 ,2 3 6 0和2 6 0 ,对 5 2 5号水泥的阻凝系数分别为 2 3 6 0 ,2 4 0 0 ,1 0 6 0和 2 2 0。与此相应的适合系数则为 2 7% ,40 % ,5 1 % ,78%和 3 4 % ,46 % ,6 0 % ,85 %。③高节竹用冷水、热水和 1 0g·kg- 1 的NaOH预处理后加入化学助剂CaCl2 ,对 42 5号水泥的阻凝系数依次为 1 2 0 ,1 1 0和9 4,对 5 2 5号水泥则为 1 0 5 ,8 4和 7 2。与此相应的适合系数则为 90 % ,92 % ,93 %和92 % ,94% ,96 %。由此可见 :高节竹对水泥有强烈的阻凝作用 ,不宜直接用于水泥刨花板生产 ;添加化学助剂能明显改善高节竹的水泥亲和性 ,其作用效果依次为CaCl2 >BaCl2 >NaCl2 >Na2 SiO3;高节竹与标号高的 5 2 5号水泥的亲和性比低标号的 42 5号水泥要强 ;预处理可明显改善高节竹的水泥亲和性 ,?

The evaluations were made on the compatibility between cement and Phyllostachys prominens wood by studying and compatible inhibitory coefficients based on temperature time curve of Phyllostachys prominens wood cement water mixture.The results showed that Phyllostachys promonens inhibitory coefficients to two kinds of cement were ∞.Comptatible coefficient to 425 # cement was 23% and to 525 # was 28%.Phyllostachys prominens inhibitory coefficients to 425 # cement were ∞,259 0,236 0 and 26 0 with each additive such as Na 2SiO 3,NaCl,BaCl 2 and CaCl 2;to 525 # cement were 326 0,240 0,106 0 and 22 0.Compatible coefficients to 425 # cement were 27%,40%,51% and 78%;to 525 # cement were 34%,46%,60% and 85% with above each additive.Addedg with CaCl 2 after pretreatments of cold water,hot watter and 10 g·kg -1 NaOH,inhibitorycoefficients to 425 # cement were 12 0,11 0 and 9 4;to 525 # cement were 10 5,8 4 and 7 2.So conclusions could be drawed that Phyllostachy prominens wood could not be used directly in cement particle board because of its high inhibition.Additives could improve its compatablity to cement.Additives' effects in turn were:CaCl 2>BaCl 2>NaCl>Na 2SiO 3.Phyllostachy prominens wood compatabillty to 525 # cement was higher than to 425 # cement.Pretreatments could also improve bamboo wood compatability to cement.The effects were 10 g·kg -1 NaOH>hot water>cold water.Only when it was used together with additives then could Phyllostachys prominens be used in half dry cement particle board production.