Ngaba iShrinkage Cracking yeConcrete eNxulumene neHydroxypropyl Methylcellulose(HPMC)?

Ukuqhekeka kwe-shrinkage yinto eqhelekileyo kulwakhiwo lwekhonkrithi kwaye lunokwenzeka ngenxa yezizathu ezahlukeneyo. Esinye sezizathu ezinokubangela ukuqhekeka kwe-shrinkage kwikhonkrithi kukusetyenziswa kwe-hydroxypropyl methylcellulose (HPMC) njengesongezo. I-HPMC iqhele ukusetyenziswa kwikhonkrithi ukuphucula ukusebenza, ukugcinwa kwamanzi, kunye nophuhliso lwamandla. Nangona kunjalo, ukusetyenziswa kwe-HPMC kunokukhokelela ekuqhekekeni kwekhonkrithi phantsi kweemeko ezithile.

Esona sizathu siphambili sokuqhekeka kokuqhekeka kwekhonkrithi ngenxa ye-HPMC kukwehla kwezinga lokulahleka kwamanzi. I-HPMC sisixhobo esisebenzayo sokugcina amanzi kwaye inokunciphisa ngokuphawulekayo izinga lelahleko yamanzi kwikonkrithi entsha. Nangona kunjalo, amanzi agciniweyo akhululwa ngokuthe ngcembe ngokuhamba kwexesha, okukhokelela ekunciphiseni kunye nokuqhekeka okulandelayo kwekhonkrithi.

Ngaphezu koko, iipropathi ze-HPMC, ezinjengobunzima bayo beemolekyuli, iqondo lokutshintshwa, kunye nokugxila, kunokuchaphazela ukuqhekeka kwekhonkrithi. I-HPMC enobunzima obuphezulu bemolekyuli kunye neqondo lokutshintshwa kunokubonelela ngokugcinwa kwamanzi okungcono kunye nokunciphisa izinga lokulahlekelwa kwamanzi, ngaloo ndlela yandisa amathuba okuqhekeka kwe-shrinkage.

Ngaphaya koko, ukuxinana kwe-HPMC kumxube wekhonkrithi kunokuchaphazela iqondo lokuqhekeka kokuqhekeka. Ukugxininiswa okuphezulu kwe-HPMC kunokubangela ukugcinwa kwamanzi amaninzi, okunokukhokelela ekunciphiseni okunyukayo kunye nokuqhekeka okulandelayo.

Enye into enokuthi ibe negalelo ekuqhekekeni kwekhonkrithi ngenxa ye-HPMC yimeko yokusingqongileyo ngexesha lenkqubo yokunyanga. Amaqondo obushushu aphezulu kunye nokufuma okuphantsi kunokukhawulezisa izinga lokulahlekelwa kwamanzi kwikhonkrithi entsha kwaye kukhokelela ekunciphiseni ngokukhawuleza kunye nokuqhekeka.

Ukunciphisa umngcipheko wokuqhekeka kwe-shrinkage kwikhonkrithi ngenxa ye-HPMC, amanyathelo ahlukeneyo anokuthathwa. Enye inketho kukusebenzisa i-HPMC enobunzima obuphantsi bemolekyuli kunye neqondo lokutshintshwa, elinokunciphisa umthamo wokugcinwa kwamanzi kunye nesantya sokulahlekelwa kwamanzi, ngaloo ndlela kuncitshiswe amandla okuqhekeka kwe-shrinkage.

Enye inketho kukunciphisa uxinaniso lwe-HPMC kumxube wekhonkrithi ukuphepha ukugcinwa kwamanzi amaninzi kunye nokuncipha. Ukongezelela, iimeko zokusingqongileyo ngexesha lenkqubo yokunyanga, njengokugcina indawo enomswakama kunye nokulawula ukushisa, kunokuncedisa ukunciphisa umngcipheko wokuqhekeka kwe-shrinkage.

Ukuqukumbela, ukusetyenziswa kwe-HPMC kwikhonkrithi kunokukhokelela ekuqhekekeni kwe-shrinkage ngenxa yeempawu zayo zokugcina amanzi. Iipropati ze-HPMC, ezifana nobunzima be-molecular, i-degree of substitution, kunye nokugxila, kunye neemeko zokusingqongileyo ngexesha lokunyanga, kunokuchaphazela iqondo lokuqhekeka kwe-shrinkage. Nangona kunjalo, ngamanyathelo afanelekileyo, afana nokukhetha i-HPMC eneepropati ezifanelekileyo kunye nokulawula iimeko zokusingqongileyo, umngcipheko wokuqhekeka kwe-shrinkage unokunciphisa.